MAMEWorld Forums - EmuChat - name the game (early 80s, spcinvaders hardware)

This ROMset has been floating around as "mr_unknown.zip", and later labeled as "unknown Model Racing game" (I doubt it's by Model Racing though). Sorry, I can't share the ROMset.

The set is missing vital parts: a section at the $4000 region, and 1KB at $0000-$03ff (game start, and irq handler resides there, so game doesn't work at all, damn). I've been studying it a bit, but can't figure out what game it is. If we can know with certainty which game it is, it could be added to MAME. It would be a shame to not share what I know.

Facts and near-facts:
- from ROM disasm: nearly certain that the CPU is i8080
- from ROM disasm:
* $0000-$1fff is ROM
* $2000-$23ff is user RAM
* $2400-$3fff is video RAM
* $4000-$???? is ROM
* $a400-$???? is color RAM
* I/O ports 0-3 are used for input and sound (I couldn't find proof that it uses a shift register, but it probably does)
- ROM has "NICHBUTSU" in it (yeah, typo)
- above statements make it near-certain that the game is running on Rolling Crash hardware (rollingc in MAME)
- after hacking and slashing with the MAME debugger and running the game as 'rollingc', I managed it to show something (no game action though =/).. the most interesting ones:
* http://crap.tsk-tsk.net/mr_unknown_h1.png
* http://crap.tsk-tsk.net/mr_unknown_h2.png
* http://crap.tsk-tsk.net/mr_unknown_h3.png
- last but not least, ROM as 1-bit picture (shuffled and rotated and whatnot, so I hope it's not against the rules :P .. about as legal as CPS2 xors): http://crap.tsk-tsk.net/mr_unknown_gfx.png

I was hoping it's Moon Raker, but I don't think it is.