Blank 2600 cartridge prototyping boards Available ?

[Ragooman]

Hello,

 

Would anyone know if there is any place that sells blank 2600 cartridge prototyping boards ?

I was hoping there some of the variety which have a grid of thru-holes, for wiring any kind of circuit - rather than just a layout of the single Rom chip design. I'm looking to make a custom circuit.

 

thanks

=Dan