[Boatanchors] Drake 2B

[Joe Connor]

Today, I picked up a very beat-up Drake 2B at a garage sale, and I need some help and advice:
 
1.  The set works well on 80m and 40m but does not seem to work on 10m, 15m or 20m. What should I be looking at to diagnose the problem? Am I correct in suspecting the crystals for those bands? (For the record, I had to replace the 6U8, which had lost vacuum, and I have to replace the 6BF6, which tests bad). I used a signal generator and could not get a signal through on 10m, 15m or 20m.
 
2.  Eventually, I would like to use this receiver for SWLing. Can anyone recommend a source for crystals? Anyone have any extras for sale?
 
3. Are there any other known issues with the 2B or any suggested mods that I should be aware of?
 
As always, thank you for your advice and guidance. 
 
 
                             Joe Connor