Making a MC44144 tester for Cobra Command / Dexter research

I've pondered about whether the "obsolete" MC44144 chip could be useful for making Bega's Battle (and Cobra Command dedicated) work with Dexter.  Although it isn't in production anymore, from what I can tell, it's still fairly obtainable.

Here's the PCB I've designed to help test it and see how well it works.