Yeah, there are missing SVGs:
https://github.com/mamedev/mame/blob/master/src/mame/handheld/hh_hmcs40.cpp#L120
http://blog.kevtris.org/blogfiles/Handhelds/VFD%20Games/

It is a lot of work.

Some guidelines:
- make source photo perfectly perpendicular before you start tracing
- no fancy stuff like glow effects or beehive pattern (see other SVGs)
- keep colors consistent for all vfds
- put segment ID in title tag as y.x where y=grid, x=plate (the ones by Kevtris need to be descrambled to match actual MCU write values but that can be done easily afterwards)

I don't remember if Coleco Zaxxon's MCU was identified.