I’d be more than happy to help, Will. If it’s the original Dynaco circuit, with the original eyelet inputs, I can email him a Dynaco manual and a picture of the original board layout and he can pretty much take it from there. The only data I’d need from you is is what tube you use in place of the 7199 and any changes you might have made. I’d also need the outer measurements of the board and the spacing of the mounting holes, but I can get those from any ST-70 replacement board. Florick is very experienced with tube circuits and will know what to do to make a nice, sturdy board. You can approve the design and I can order the boards from China for you. They cost, like $3 each. I could order a few and you can try them out. I’m right next door in Southern Oregon. No need to raise your blood pressure! ;-) If they don’t work out no harm done.
Believe me, the Williamson boards he designed for me are wonderful. They measure beautifully and are dead quiet, no ground loops, no issues at all. I love them. I was in the same spot as you, thinking how in the world could I get this accomplished, and in fact it was incredibly easy.
I’m semi-retired myself but my wife still works full-time and this sort of thing keeps me out of her hair.