Generally, if something is "not working quite right" it is NOT a tuning issue. Components do age over time requiring replacement (usually these days, with $$$ the big issue in repair departments, that means "board replacement" not parts replacement). And that is a transformer not a potentiometer. It is a couple of coils or one coil wound on a cylindrical form, with that red tuning slug (ferrite material in a round, screw-like configuration) going into and out of the can to vary the resonant frequency of the coil or transformer. Not having a schematic, I can't tell you what T2 tunes or what frequency it should be tuned to. You would need a desoldering station, magnified lamp, anti-static mat, small thin solder and several small hand tools to fix this, assuming you could obtain the transformer. I have had some success, (repeat, SOME) in desoldering the can and leads and removing the can from the board and removing the cracked/broken pieces of ferrite slug material from the can and then finding a new slug and hoping it's characteristics were close enough to those of the original slug to work as a replacement. It it highly risky to repair, but it can be done. Good luck.
EMT911, Bob