Do you knows a source of spare parts for Fluke ?
First off, know that I don't anything about repairing an oscilloscope; I wouldn't even know where to begin, so you have that up on me with your testing!
For parts, you might try getting in contact with this company:
They helped me get a "new" (surplus) implosion shield for my Tek 2213 (it was actually a spare from some East European country); it wasn't very expensive, and they were very responsive with their entire order and service process. I was very impressed with them as a company.
I can't promise you it will work out, but its someplace to start, at least!