I wouldn't do much with the floats until you can confirm all passages are clear. If you find any other blockages while cleaning, I'd leave the float level alone. If everything appears clear already, lowering it a little (1/8" or so) may not hurt but be prepared to raise them if you run into WOT issues later ;)
Let u know what happens
Old cars, the tinkering never ends
Where is your fuel filter? After the pump, right?
YES Filters can still let some gunk get by, but a good one shouldn't let too much pass. There's plenty of discussion here and elsewhere on various filters and their effectiveness. I don't think it needs to be overkilled just yet though. It's probably more to do with varnish than chunky stuff
(from where? tank? because I had cleaned the bowl really well). The color might give you a clue if the tank is a bit rusty though.
On the outside it looks new but, I guess that doesn't necessarily mean much where it counts, on the inside.
I wouldn't run premium either
Got it!- 87 for a stockish motor is adequate and will burn better in my experience. After a few tanks, I would imagine the old stuff is pretty well diluted, yes.