[peteri]

Sadly you've missed a recent opportunity with the Minstrel Forth https://www.thefuturewas8bit.com/shop/tynemouth-products/min... a modern clone of the original. There is a bit of cheating by having a micro controller do the video timing along with a dual port RAM for the video, but I'm happy enough with that.

Alternatively you could go with Grant Searles schematic http://www.jupiter-ace.co.uk/hardware_diy_ace.html

[Gordonjcp]

I have a circuit diagram and Kicad, and it wouldn't cost much to get a board made.