Mitsubishi 'MA7054' reproduction

Recently me and my mate "Hammy" worked together on a custom chip reproduction project.The chip is marked 'MA7054' (manufactured by Mitsubishi as logo proves) and it's found on some Tecmo PCBs like World Cup '90 and Tehkan World Cup  :

The package is SIL, same of the 'MA7053' (reproduced as well),  another custom IC found on Tecmo PCBs but pin counting and spacing are different ('MA7054' is 15 pin 2.54mm whereas 'MA7053' is 28 pin 1.778mm).You can read more about the 'MA7053' here :

Mitsubishi 'MA7053' reproduction

'Hammy' traced the connections of the chip on an orginal board and studied its behaviour making comparison with some bootlegs we sourced.He ended up in an equivalent circuit which I routed to a proper board :

The testing of the reproduction on a Tecmo World Cup '90 was successful :

 

Thanks again to 'Hammy' for his invaluable help.