The transformer secondary is now completed and I am ready to do some further tests to test it's abilities. I have bumps the winding up a bit to leave a little voltage room for when a load is applied, but the voltages may be higher than really necessary.
Transformer was connected to mains and the 42 volt winding was applied to the rectifier bridge and a very serious issue was discovered. The body of two diodes that had to be mounted on the same heatsink were at the two different AC potentials. I had shielded the screw with Kapton tape, insulated the lug with a nylon washer, and used a nonconductive thermal interface material and could not get continuity between the two diode bodies. Despite all of this, the application of the 42V winding arced through the TIM, burned open the Kapton, and then shorted the screw to the heatsink. The massive current spike spattered TIM and blew the fuses. Unfortunately insulation may not be enough so at my next opportunity I will slice the heatsink in half to provide complete electrical isolation.