dudleydes…… thankyou thankyou thankyou thankyou thankyou thankyou.
I didn’t install from source originally so it was missing the src folder. I downloaded the mame4all-pi source from github and modified minimal.cpp as you showed. Compilation took AGES !!!! Replaced the existing mame4all-pi folder with the new compiled one and modified the mame.cfg file for the roms and samples.

BINGO. works perfectly. Thanks again.