Sega '315-5012' reproduction

Here is a new reproduction of a custom IC I recenty made.This time I took into account the one marked '315-5112' found on Sega System 1/2/16A PCBs as well as unique hardware like Space Harrier and Hang On.Techically speaking it's a 48 pin DIP part (600mil wide) which accomplishes graphical functions generating the sprites and it's always used in pair with the smaller '315-5011' (which is the sprite line comparator) 

As always I studied how functions of this custom IC were reverse-engineered on bootleg boards.I was able to extrapolate the equivalent circuit and routed it to a proper board layout using thru-hole parts for this first testing made just to validate schematics:

 The replacement board worked fine :

Happy with result I decided to do a version based on an Altera +5V CPLD :

The hardware is made but software part not yet due to my limited knowledge with complex programmable logic and hardware description language so any help is welcome!