I am easily confused to be fair, Maybe I saw ghosts when I looked at the sources.
Eitherway at startup Mame clearly says i8086 and not NEC V30 so the right one is probably configured in the driver.
Despite in mame 0.241 when checking the systeminfo with SystemInfo by Norton Utilities v1.0 I get really funny results:
There is definitely something going bad with the si tool with this driver.
NEC V20 - I have no idea about the cpu check code being used in by Norton though, but an 8086 should return positive on the bus width test for 16 bit.