Rebuilt the Rectifier module today, I left the Seleniums in for future historians to marvel at, meanwhile I mounted the 600V PIV Diodes on a terminal strip along with a couple resistors to drop the voltage a bit.
The metal clips are just disc brake anti rattle clips that happen to fit perfectly to hold the resistors against the metal bracket, that should help dissipate some of the heat.
The metal cover will keep them from coming off.
I figure the heat from the resistors will warm the Seleniums just enough for them to give off that nostalgic vintage electronics smell.