Looked further - the 80C26-2 has a higher current rating on the 6.3V winding, else it's the same as the 80C26-1. The additional current capability was to power the phono amp tubes. Both cross to the same Thordarson and Triad part numbers, so the mounts are apparently the same, and both sets used a 6W4 damper, with the filament fed from the power tranny, no separate filament transformer for the damper.
Triad's cross reference is online if you need it:
http://www.triadtransformers.com/tv81.html
So if you need a transformer, give Play Things of the Past a call. They are likely the only ones out there with a tranny.
http://www.oldradioparts.com/2a23efl.txt
4593-003 POWER ADMIRAL 80C26-2 300-0-300V @200ma, 5V @3A, 6.3V @8A, FIG 2, BOT WIRES,USED 1 4 1/8 3 1/8 3 3/8 $17.00
And no, I have no affiliation with PTOP, except being a customer in 2010, for a part for my Dad's RCA 721TS.
Cheers,