Cool idea---- i've converted many CHB50's and CHB35A's to other circuits---i like to see what others come up with with these amps.
i recently finished an AA964 Princeton-ish build myself, no pics yet--- my amp is a 30 watt 6L6GCx2, cathode biased, no Trem---i built it with a variable NFB pot but i've found that i like the amp with no feedback-- so i'll remove the NFB circuit, Pot and use the front panel hole for a crossline MV.
i used a PT from a Dukane 30 watt PA head and an OT from a similar, but older, Stromberg-Carlson PA head--- an AES 125C1A choke.
Amp has a rich, creamy tone and is a blast to play---i built it on a new Hammond steel chassis w/turretboard.
The other night a friend stopped by my workshop looking for "something better" for his stage amp, w/his Strat (plays Texas Red Dirt music)--- he played several amps but liked a Bogen CHB50 converted to a Fender 6G7-A Brownface Bandmaster circuit (no Trem) the best--- he also uses an Ibanez multi-effect unit and has a limit on his stage volume due to their band sound engineer---we now have plans to build a Brownface Vibrolux-type amp into a blown solid-state 2X10 Ibanez combo i have laying around.
We found that he was getting the best lo-vol tone with the CHB50-based head----- he played a 15 watt AA964 JJ 6V6S head i built with a nice 60's Schumacher 4/8/16 OT that sounded great but he was getting more sustain/harmonics out of the CHB50-based 6G7-A..............gldtp99