Sean what you have to realize, is that retuning a radio is a simple 
operation.  Let alone does it give you the best possible signal, but it 
protects your equipment and valves.  Those valves are not going to get any 
easier to find over the years, hence forth, their price will continue to 
rise.  If you are kind to your radio, it is possible to get twenty years out 
of a set of finals.  That means tune your finals, and make sure the radio 
sees a flat SWR.  The audio oscellator is more accureate than the meter. 
Backk off the drive until you get comfortable with the process.  10 watts 
will be plenty for adjustment power.  I ran a set of 6JB6 sweep tubes for 25 
years on that system.  Those are no near as rugged as the 6146 tubes that 
the kenwoods used.