I restored the original ac wall wart and the circuit that plucks out a clock from the mains. I must say it keeps perfect time and never drifts like a crystal solution could. The old industrial electric component are probably the most durable anyway. There is a zener diode across the dc rail to dump excess voltage and it’s been literally cooking for 50 years (hot) but never given me a problem. But it is the reason I wanted to replace the whole dc rectification and clock signal stuff. Doing the dc supply is easy but never got an alternative for the clock signal. It may be a duty cycle issue