i can add a few
the rca panel on the rear, has the rca connectors really close to eacother, i suppose back in the days when they connected the 12z the plugs were not so thick and they flushed perfectly on the connectors w/o touching eachoter.
Todays RCA heads are so thick that it causes the solder jacks inside to become loose and eventually break off the panel.
Another wonderful thing you should know, check each pot very "closely" one test i like to do is to max out the pot all the way to 10 and check to see if the sound balance is in tact. I had 3 pots that had the leftside side cut out whenever these pots were maxed out, and the other 3 were fine with know issues.
Most vintage Urei's have oxidization on the chassis which is perfectly fine and does not affect the circuitry at all. Hope this helps