Check if your oscillator tube, XXL, is operating. You should have a negative grid voltage when it operates. Swap tubes if it doesn't operate. These tubes can be on the verge of oscillation. Coil location can make a difference.
Other than that there are only switch contacts. Since you already cleaned them make sure no contacts are broken.
Norm
: Help! local oscillator will not operate in push button position, radio works fine otherwise on all bands, have replaced caps, cleaned switches, etc. Resistors and wiring check OK. Riders 12-63