Well, my 1965 book (winged) has the 110 only transformer. The 1968 and
subsequent books all show the split primary. Greater Collins minds than
mine will have to give you a serial number relationship. Having said
that, it does appears that a round power supply will have the 110/220
capability. So, if its a round your interested in, I'd bet the ranch
that it'll work on both input voltages.

Mauro Succi wrote:
Is there a known S/N when the production switched to split primaries?
Can i assume that all round emblem units have split primaries?
A couple of time I've asked sellers that info, but never got exaustive
answer.
So i'm still waiting to bid.
Mauro