Well, we still don't know exactly what's going on, we just know that something is drawing too much current when the tubes are in the amp and the circuits are complete.
My next step, since I have a tube tester, would be to test the tubes. If you don't have one available, I always recommend looking in the phone book to see if there is a guitar shop in your area that repairs tube guitar amps. They usually have a tester of some kind.
In the meantime, since you can now power up at least part of the amp, it may be useful to try to get some Voltage readings. Expect them to be mostly higher than in the manual, since the tubes are out.
A good place to start, I think, would be the tubes socket pins on each socket. Post those back here. Note: IIRC, the readings should all be DC and with respect to circuit ground.
BTW, even though the fuse is holding, I would not recommend leaving the amp "On" any longer than it takes to get a few quick readings. Doing so can tend to lead to some complacence, and even without the tubes in place, there is still ample opportunity for a nasty shock!
