My Brand New CTC-7!

[dtvmcdonald]

Its probably not the crystal. They seldom change frequency.
More likely are the 220 and 82 pF caps attached to it and
the15 pF cap across L704.

Also ... have you tried turning C740 (RCA schematic), noting where it
was originally set.

But as I said before, the next step is to try playing with the cathode to
grid voltage on the reactance tube and see how it changes the frequency.
Making a bias box is easy, just use a 9v transistor radio battery.