Good to hear, Sean. Is there any sort of list for wanted TMS chips (or other microcontrollers)? You might find some interesting items on this page:

I don't know that I have any more TMS chips. I do have a few old handhelds, like Mattel Auto Race, which is a really early electronic game. Here is an interesting interview with the programmer:

hap, I know that the Mathemagician had overlays for various games. I'm not sure exactly how it worked, though.

Incog had some overlays. I haven't seen him on here lately, but I'll try to get in touch to see if he can re-upload them.