Sounds like you picked the wrong crystal for 10m - to me.
Using a DPST switch, stock/and 10m crystals, small piece of breadboard, and two variable caps, it might be possible to run both. Two parallel circuits and a switch between them - basically. Never done it myself; but in theory it might work. All you would need to do is wire both crystals/variable caps on a board and then wire them to the main board where you took the stock crystal from. Only one problem that I see, is that the VCO voltage might not be right for both bands and might unlock the PLL on one band or the other. Even that can have a workaround.
The OTHER consideration is to open the clarifier and use a 'super diode' (diode/choke) so that it will slide ~6kc's.
Re-aligning the VCO, 1st osc, and 2nd osc will be necessary too.
Will it work?
Maybe; maybe not . . .