I made my circuit using NOS parts from BG Micro electronic supply and it worked. As a test I ordered some new PUTs and they failed to function? The ohmmeter test reviled the devices are SCRs not PUTs. It maybe possible to rework the design and get it to function but they devices are not direct substitutes. They are marked as the same device but the PUT gate is an anode gate and the SCR gate is a cathode gate.
I may spend a rainy day testing the new devices but for now just be aware. I used the PCT tester with the BG Micro part and it passed. The new part does not pass. It could be a matter of changing the supply polarity?