Measure numbering: Volta with incomplete alternatives

[Sam Bivens]

Hi all,

I'm typesetting a Beethoven bagatelle (119/4) where both alternative measures at the end of a volta are incomplete. If you look at the attached PNG, you'll see that the measure immediately following the second alternative is also incomplete (it's the start of the third system). LilyPond gives this half-measure it's own measure number, as shown in my attached MWE. I have two questions:

1. Are there any sources in the notation literature that give a suggestion on how we should number these measures? Should the half-measure at the start of the third system get its own measure number, or should it be a continuation of the previous measure (in my Lily file, 2b)? My intuition suggests the latter.
   
2. Are there cleaner ways of fixing this than my three commented-out lines?

(And a bonus question if anyone knows: why isn't this bagatelle written starting on beat 1?)

Thanks for any help anyone may offer!

Sam

b_119_4.png
Description: PNG image

measure_numbering_mwe.ly
Description: Text Data

measure_numbering_mwe.pdf
Description: Adobe PDF document