I can't find the schematic anywhere, but if the B+ supply uses a standard doubler circuit, it should be one of the two configurations shown here..
http://www.electronic-circuits-for-h...-two-diode.php
The banded end of the Si diode denotes the cathode. Seleneums frequently had a '+' sign denoting the cathode, which is counterintuitive as hell. But that was the convention.