Repair/replace tube for Panasonic projection TV?

[TTTembo]

I need to fix the weak/dead blue tube in my Panasonic projection TV. The TV
is showing mostly red & green.

Option 1 - Repair
- is this possible?
- can the electron gun be replaced?

Option 2 - Replace
- would like a used tube to minimize costs
- new tube would be nice if cheap enough, but may overpower older red &
green tubes?

Does anyone know a repair guy in the Toronto area who can handle this type
of job?

Thanks in advance!
slivercd@hotmail.com