use eval to emit only part of a rule?

[Britton Kerin]

I'd like to use eval to emit some boilerplate vars and everything
short of the prereq list for a
static pattern rule.  Is it possible?  This is as close as I came:

# Production Stamp Target Header Template
PSTHT =                                 \
$1_STAMPS = $$(PBT:.pcb=.$1.stamp)$(nl)  \
PRODUCTION_STAMPS += $$($1_STAMPS)$(nl) \
vpath %.$1.stamp $$(STD)$(nl)            \
$$($1_STAMPS): %.$1.stamp

# Stamps meaning parts for a given board have been ordered
$(eval $(call PSTHT, parts_ordered)): \
  %.$(GIT_VID).multivendor_bom.csv       \
 [snip]

Oddly if I put the : inside the template I get missing separator
(syntax error).  The above passes
syntax but then I get No rule to make target.  Maybe it just isn't
possible to split things up like
this?

Britton