Public data, catalogs, and application notes on General Electric products.
GE 1959 Designing with Vac-U-Sel Component Rectifiers - It is 1959, so germanium and silicon rectifiers are essentially mature, leaving little need for selenium rectifiers. But for those engineers who are nostalgic, GE offers lots of design information.
GE ECG-402 Application Notes on GE Vac-U-Sel Rectifiers - Although intended for selenium rectifers, this app note is very applicable to general rectifier/power supply design. Good info here.