OK. I checked both fuses and they looked fine. There was some white powder in the fuse slot--whatever that means? I swapped out the PI tube (third from left...closest to power tubes) and now the amp seems fine. There is still a slight electrical smell when I get my nose close to the back of the head. It is not as strong as before. This might be normal since some say tube amps have some smell...don't know for certain.
It appears that patrickhowell may have found the issue.
I can have the suspect tube tested just to confirm. Is this a good idea?
Also, I guess it wouldn't hurt to have a tech go over it to make sure. I got such a good deal on the amp I don't mind a little investment in a tune-up. Got a quote for $75 - $100 for a thorough check-up. Sound about right?
Thanks for all of your help. My son will be psyched to gig with a real Marshall stack.