[TenTec] Corsair II PBT Question

[K4MT]

My Corsair II has a problem with the PBT adjustment. I can not get the SB-N and SB-R to sound the same.  When I adjust coil L4 the closest I can get is with the slug all the way to the top which raises the frequency f the 15.3012 crystal.  I measured the frequency range of the 15.3012 oscillator and it varies from 15.3012 with the PBT control full CW to 15.2969 full CCW,  I found that SB-R audio quality is very tinny. I was wondering since the crystal reads 15.2969 with PBT CCW (no voltage on the varactor) means the crystal is too low in frequency. Tentec  wants 30 shipped so before I order one I was wondering what the experts on this group think.
I have aligned the carrier oscillators so that is not the problem. It is the same on all bands and all crystal filters ( I have 2.4, 1.8, 500 and 250). Do you think the 15.3012 crystal is out of specs or is it something with the 2.4 9 MHz filter?