This is an alternative refurb diagram, from John Byms 

URL: http://users.rcn.com/jbyrns/stuff/BE-5B.jpg

This version uses a single full-bridge rectifier to accomplish both the 6-volt 
full-bridge and the 12-volt voltage doubler mechanism.

This involves stripping most of the connections from the switch. 

John's Notes, from reg.antiques.radio+phono...

"The modification is simple, the original selenium rectifiers and all the
connections to the switch except those going to terminals 1, 10, 11, & 12
are removed. The new bridge rectifier is then bolted to the chassis in a
suitable location and the loose yellow transformer wire, removed from
switch terminal #4, is connected to one of the AC input terminals on the
bridge rectifier. The remaining three terminals of the bridge rectifier
are then connected to the points indicated on the schematic using suitable
pieces of wire.

If a terminal on one of the original selenium rectifiers was used as a tie
point for any of the wires going to switch terminal #11, this connection
must somehow be retained, either by using one of the bridge rectifier
terminals as a tie point in a similar manner, or by moving the affected
wires to another point connected to the negative output bus."