The Johnson 6N2 may not be the best choice for a linear amplifier
conversion, although I am not sure what you mean. If you mean to use the
cabinet to build a low band amplifier, it seems like it would be easier to
start over. If you mean for vhf use, the output tube does not have a lot of
plate dissipation, so would not be a good linear amplifier for the vhf bands
either.

It would be more easily converted to a transverter, which could also be more
useful.

There seems to be a bit more interest in 6 meter am, and the unit may be
more valuable as is.

Colin K7FM