Possible Open-licenced SVG (vector graphics) replacements for existing enigma 
(bitmap) images. Unless otherwise specified, .svg suffices apply for replacements.

Sources: 
[tp] http://tango.freedesktop.org/ (Licence: CC-SA)
[oc] http://openclipart.org/ (Public Domain)
[nuvola] Nuvola (LGPL)


As of gfx48 directory:

ac-blackball-fall.png
ac-blackball-jump.png
ac-blackball-shatter.png
ac-drowned.png
ac-whiteball-fall.png
ac-whiteball-jump.png
ac-whiteball-shatter.png
ac-whiteball-small-fall.png
ac-whiteball-small-jump.png
ac-whiteball-small-shattered.png
ac-whiteball-small-shatter.png
dummy.png
expl.png
fg-blackball.png
fg-blackball-sink.png
fg-bug.png
fg-horse.png
fg-rotor.png
fg-top.png
fg-whiteball.png
fg-whiteball-sink.png
fg-whiteball-small.png
fl-abyss.png
fl-acblack.png
fl-acwhite.png
fl-black.png
fl-bluegray.png
fl-bluegreen.png
fl-bluegreenx.png
fl-brick.png
fl-bridgea-closed.png
fl-bridgea-open.png
fl-bridgea.png
fl-bridgex-closed.png
fl-bridgex-open.png
fl-bridgex.png
fl-bridgey-closed.png
fl-bridgey-open.png
fl-bridgey.png
fl-bumps.png
fl-concrete.png
fl-darkgray.png
fl-dummy.png
fl-dunes.png
fl-floor_001.png
fl-gradient2.png
fl-gradient-wiz.png
fl-gravel.png
fl-gray.png
fl-hay.png
fl-himalaya.png
fl-ice-heating.png
fl-ice.png
fl-inverse2.png
fl-inverse.png
fl-leaves.png
fl-lightgray.png
fl-light.png
fl-marble.png
fl-metalb.png
fl-metal.png
fl-mortar.png
fl-nomouse.png
fl-normal.png
fl-plank.png
fl-red.png
fl-rock.png
fl-rough-blue.png
fl-rough.png
fl-rough-red.png
fl-sahara.png
fl-samba.png
fl-sand.png
fl-space.png
fl-springboard.png
fl-stone.png
fl-stwood.png
fl-swamp-heating.png
fl-swamp.png
fl-tigris.png
fl-trigger.png
fl-water-heating.png
fl-water.png
fl-white.png
fl-wood.png
fl-woven.png
halo-blink.png
halo.png
halo-small-blink.png
halo-small.png
ic-marble.png
inv-blackball.png
inventory.jpg
invisible.png
inv-whiteball.png
it-bag.png
it-banana.png
it-blackbomb-burning.png
it-blackbomb.png
it-blocker.png
it-booze-broken.png
it-booze.png
it-brush.png
it-burnable_ash.png
it-burnable_burning.png
it-burnable_fireproof.png
it-burnable_ignite.png
it-burnable_oil.png
it-cherry.png
it-coffee.png			http://commons.wikimedia.org/wiki/Image:Emblem-relax.svg [LGPL]
it-coin1.png
it-coin2.png
it-coin4.png
it-crack.png
it-cross.png
it-death.png
it-document.png
it-drop.png
it-dummy.png
it-dynamite-burning.png
it-dynamite.png
it-extinguisher.png
it-extralife.png
it-flagblack.png
it-flagwhite.png
it-floppy.png			media-floppy [tp]
it-glasses-broken.png
it-glasses.png
it-hammer.png
it-hill.png
it-hollow.png
it-hstrip.png
it-key.png
it-landmine.png
it-laser.png
it-magicwand.png
it-magnet-off.png
it-magnet-on.png
it-odometer.png
it-pencil.png
it-pin.png
it-pipe.png
it-puller.png
it-ring.png
it-rubberband.png
it-seed.png
it-shogun-big.png
it-shogun-med.png
it-shogun-small.png
it-spade.png
it-spoon.png
it-spring1.png
it-spring2.png
it-springboard.png
it-squashed.png
it-surprise.png
it-sword.png
it-tinyhill.png
it-tinyhollow.png
it-trigger.png
it-umbrella.png
it-vortex.png
it-vstrip.png
it-weight.png
it-whitebomb-burning.png
it-whitebomb.png
it-wormhole.png
it-wrench.png
it-yinyang.png
Makefile
Makefile.am
Makefile.in
menu_bg.jpg
ring-anim.png
sh-actorimpulse.png
sh-blackball-jump.png
sh-blackball.png
sh-blackball-sink.png
sh-brake.png
sh-doorh.png
sh-doorv.png
sh-floating.png
sh-glass.png
sh-grate1.png
sh-grate2.png
sh-grate3.png
sh-horse.png
sh-pull.png
sh-puzzle1.png
sh-rotor.png
sh-round2-growing.png
sh-round2.png
sh-round.png
sh-shogun1.png
sh-shogun2.png
sh-shogun4.png
sh-solid.png
sh-top.png
sh-white4.png
sh-whiteball-small-jump.png
sh-whiteball-small.png
st-actorimpulse.png
st-beads.png
st-bigbluesand.png
st-bigbrick.png
st-black1.png
st-black2.png
st-black3.png
st-black4.png
st-blackballs.png
st-blocker.png
st-block.png
st-bluegray.png
st-blue-sand.png
st-bolder-fall.png
st-bolder.png
st-bombs.png
st-brake.png
st-break_acblack.png
st-break_acwhite.png
st-break_bolder.png
st-break_gray.png
st-break_invisible.png
st-break.png
st-brick.png
st-brownie.png
st-bug.png
st-bumps.png
st-camouflage.png
st-chargeminus.png
st-chargeplus.png
st-chargezero.png
st-chess_black.png
st-chess_white.png
st-coin2slot.png
st-coinslot.png
st-death.png
st-disco.png
st-doorb.png
st-doorh.png
st-doorv.png
st-dummy.png
st-dynamite.png
st-easymode.png
st-fakeoxyd-blink_0001.png
st-fakeoxyd-blink_0002.png
st-fakeoxyd-blink_0003.png
st-fakeoxyd-blink_0004.png
st-fart-break.png
st-firebreak.png
st-flash.png
st-flhay.png
st-floppy1.png
st-floppy2.png
st-flrock.png
st-fourswitch.png
st-glass1.png
st-glass2.png
st-glass3.png
st-glass.png
st-grate1.png
st-grate2.png
st-grate3.png
st-greenbrown.png
st-key1.png
st-key2.png
st-knight.png
st-laser-base.png
st-laser-e_0001.png
st-laser-e_0002.png
st-laser-e_0003.png
st-laser-e_0004.png
st-laser-e_0005.png
st-laser-e_0006.png
st-laser-e_0007.png
st-laser-e_0008.png
st-laser-e_0009.png
st-laser-n_0001.png
st-laser-n_0002.png
st-laser-n_0003.png
st-laser-n_0004.png
st-laser-n_0005.png
st-laser-n_0006.png
st-laser-n_0007.png
st-laser-n_0008.png
st-laser-n_0009.png
st-laser-s_0001.png
st-laser-s_0002.png
st-laser-s_0003.png
st-laser-s_0004.png
st-laser-s_0005.png
st-laser-s_0006.png
st-laser-s_0007.png
st-laser-s_0008.png
st-laser-s_0009.png
st-laser-w_0001.png
st-laser-w_0002.png
st-laser-w_0003.png
st-laser-w_0004.png
st-laser-w_0005.png
st-laser-w_0006.png
st-laser-w_0007.png
st-laser-w_0008.png
st-laser-w_0009.png
st-lightpassenger-break-h.png
st-lightpassenger-break-hv.png
st-lightpassenger-break-v.png
st-lightpassenger.png
st-magic.png
st-mail.png
st-marble.png
st-metal.png
st-mirror-movable.png
st-mirror-static.png
st-mirrortempl_0001.png
st-mirrortempl_0002.png
st-mirrortempl_0003.png
st-mirrortempl_0004.png
st-mirrortempl_0005.png
st-mirrortempl_0006.png
st-mirrortempl_0007.png
st-mirrortempl_0008.png
st-mirrortempl_0009.png
st-mirrortempl_0010.png
st-mirrortempl_0011.png
st-mirrortempl_0012.png
st-mirrortempl_0013.png
st-mirrortempl_0014.png
st-mirrortempl_0015.png
st-mirrortempl_0016.png
st-oneway.png
st-oxyda-opening.png
st-oxyda-open.png
st-oxyda.png
st-oxydb-opening.png
st-oxydb-open.png
st-oxydb.png
st-oxydbtempl_0001.png
st-oxydbtempl_0002.png
st-oxydbtempl_0003.png
st-oxydbtempl_0004.png
st-oxydbtempl_0005.png
st-oxydbtempl_0006.png
st-oxydbtempl_0007.png
st-oxydbtempl_0008.png
st-oxydbtempl_0009.png
st-oxydbtempl_0010.png
st-oxydbtempl_0011.png
st-oxydbtempl_0012.png
st-oxydbtempl_0013.png
st-oxydbtempl_0014.png
st-oxydc-opening.png
st-oxydc-open.png
st-oxydc.png
st-oxydd-opening.png
st-oxydd-open.png
st-oxydd.png
st-oxyd-questmark.png
st-oxyd-symbols.png
st-plain.png
st-pull.png
st-puzzle.png
st-redrock.png
st-rock10.png
st-rock1.png
st-rock2.png
st-rock3-break.png
st-rock3_cracked.png
st-rock3-falling.png
st-rock3.png
st-rock4.png
st-rock5.png
st-rock6.png
st-rock7.png
st-rock8.png
st-rock9.png
st-rotator-left.png
st-rotator-right.png
st-rubberband.png
st-scissors.png
st-scissors-snip.png
st-shogun.png
st-stone1.png
st-stone2.png
st-stone_break.png
st-stoneimpulse-hollow.png
st-stoneimpulse.png
st-surprise.png
st-swap.png
st-switch_black.png
st-switch.png
st-switch_white.png
st-thief-captured.png
st-time1switch.png
st-timer.png
st-timeswitch.png
st-turnstile-green.png
st-turnstile.png
st-white1.png
st-white2.png
st-white3.png
st-white4.png
st-whiteballs.png
st-whitebombs.png
st-window.png
st-wood_001.png
st-wood-growing.png
st-wood.png
st-woven.png
st-yellow.png
st-yinyang1.png
st-yinyang2.png
thief-captured-template.png
thief-template.png