I'm in Oz.. postage/freight from here is even more horrific - I feel yr pain.. truly..!
Some of the things U describe seem almost normal - EQ touchy..
It'd need a bench, chase a signal, check for anomalies - poss to find no actual fault but abberation of "normal" with some tweaking to make it less responsive..
"Noisy".. accurate description needed incl when it occurs to give any meaningful help..
Re loose choke ( one will be rev drive tranny - it'll have 4 leads not 2) - def tighten. ASAP. Check all chassis-mounted objects INCLUDING jacks/pots.
If clean ch sounds OK that points less to power end and more preamp end.
BUT.. BUT.. not guaranteed. Dare I say needs a bench..
If new tubes throughout and symptoms persis, that leave PCB / component / wiring anomalies. Don't neglect earthing too.
Long story short.. your symptoms are so wide and variable that accurate help here will be bloody hard.
Local tech should be a starting point I'd humbly suggest..
Mk IIB,export,rev, tweed tolex !!
Mk IIB,export, rev,GEQ,simul, black
Mk III head,rev,GEQ,cream
Kitty Hawk M1 head
Fender 75, export, 1973,15".
Fender 6G6A Bandmaster 1962
Fender AA763 Bandmaster 1964