[MrFixr55]

Roy, you may have hit in something (Sorry about the pun). The giveaway is the static that you receive as you rotate the cap. Go back and forth tuning. If you can reproduce the "scratch" at the same dial indication on all bands, there is your smoking gun.

Generally, the spacing between rotor and stator plates of a tuning cap should be consistent except for the end plates which have notches, that allowed sections of these plates to be bent for better tracking. Look at the cap carefully. There may be adjustments for centering the rotor and stator. Some sets have an adjustable bearing on the rear of the cap. Adjusting this may stiffen the cap but may push the rotor plates to a correct position.

Try to flex the tuner itself to see if this changes things. Flex the chassis in an area where the cap is not affected These techniques may help find intermittent operation caused by mechanical issues. You may be looking at multiple issues.

Many times, connections to the chassis are through rivets that may get loose and connect poorly. Good HiFi amps and even one radio in my collection have "Ground Busses", a thick wire where all "returns" are made. This bus connects to the chassis at only one point. Unfortunately, most mass-produced transformer powered sets don't work that way ("Warm chassis" transformer sets do have a "ground Mecca" centered around the 1st Audio tube.