I'll raise my hand (oooh! oooh!) as I have had one since early 1968...
As Steve (default) and I have discussed, the "J" in the moniker may be for "Jazz." Definately NOT Fender tweed
Deluxe sounding, very very clean up to almost full blast, only one half of one preamp tube used for each channel's
gain. Think more like a non-reverb SF Fender Princeton. Trem is very nice, alas mine has been repaired twice (second time by Steve) and its wonky again, probably because I do not use her anywhere near enough now.
Pot date-coding mine makes it a '63 (even though it has an older Jensen blue); based on the covering, the handle and
the switches (not ball end), I would guess yours newer. Do not know if your vintage still had the frosted green pilot light lens.
Nice job on the recap! Just make sure to do something about that nasty death-cap in there
Oh, and NICE mono-blocks you got there! Wow!