Got this board as fully working
I immediately noticed some problems on the sprites
Transparent objects and shadows were solid and some sprites had glitches
Konami maskroms are known to be unreliable so I ran immediately the maskrom test reveling that rom @25g was faulty.
Before desoldering I checked also the custom underneath which sometims has pins lifted but it was good.
Upon a close inspection I saw some rust on 3 pins of the maskrom @25g which in my opinion could be the reason of the fault
Therefore I decided to desolder it and resolder a 27c160 programmed with the correct file
Board 100% fixed