WOW!!! what a great price! $2.00, I cannot believe that! Dad bought his Fisher 400 back in 1964 for $300 with the wooden case, the XP5 speaker systems, and a Garrard turntable. That was a pretty stiff price back then, but was still pretty high when you consider inflation, and the fact that they are worth more now than when they were new!
I spent many nights down in the basement listening to records with Dad with the fireplace burning. That stereo ruined me for life, because I am now so picky about what a good stereo supposed to sound like! That stereo continued to survive my sister's wild teenage parties, and my own teenage years where my friends and I would crank it up and play it loud! Dad still enjoys that stereo today.
As an electronics technician, I did some repairs for Dad. The big electrolytic capacitor in the power supply is guaranteed to go bad, and will put hum into the audio (the audio output should normally be perfectly silent even at full volume with no signal present!) I also recommend replacing the selenium rectifier with a silicon one. The 7868 tubes will read no higher than 60% on a tube checker...don't think they are weak. These tubes last a long time and rarely need replacing unless the stereo's lived it's life as a P.A. system amp. That is good, since they can be rare and expensive. If anything, the 12AX7 tubes used in the pre-amp stages may need to be refreshed. I recommend buying some good Russian tubes like Sovtecs to replace them if they are weak on the tube checker. Also, test the FM receiver tubes. If these are the slightest bit weak, FM recieption will suffer greatly. Luckily, they also rarely go bad. Most of the coupling capacitors underneath are ceramic, and will never need replacing. Also, make sure to keep up with the center caps on the knobs...the glue tends to go bad, they fall off and get lost. I believe Antique Electronics supply and Vacuum Tube Valley both have replacements for these!
Have fun with your new stereo! Those things sound awesome!