I recently recapped a 1946 Sentinel 294T AM/SW radio. It plays, but after aligning it, the IF oscillates at several places in the AM band. Detuning the IF will solve the oscillation, but noticeably reduces the gain. Any suggestions on how to solve the oscillation and keep the gain?

AM sensitivity is excellent and the gain tracks pretty well across the band. (6 tube set with an RF stage).

However on SW 5.7Mhz to 18.3Mhz, the bottom of the band suffers low sensitivity. It is quite sensitive from about 9Mhz through 18Mhz. There is no padder or coil adjustment for the bottom of the band, only for the top. Any suggestions on how to improve the gain on the bottom of the band? I can't tell if it needs more or less inductance.

The schematic is here http://www.nostalgiaair.org/Resources/143/M0018143.htm

Thanks in advance for any assistance.