I just paid the price for a couple of 7199s.
First item, for safety's sake, was to replace the Selenium rectifier in the negative bias supply circuit with a generic silicon one. You don't want to run the risk of breathing the results of a Selenium diode going "poof", I am told. I just mounted a little 3-terminal strip to the screw that holds the Selenium stack in place to mount the silicon diode. Since that bias supply is important, I replaced the caps and resistors in it while I was at it.
A new multi-section cap for the main supply was to be had at Antique Electronics Supply. They were actually manufacturing a drop-in replacement.
The plating on the input connectors is usually pretty grim, so I replaced those with a couple of cheap gold-plated ones from RS that fit into the same phenolic insulator that the old ones were in.
A three-wire power cord, again for safety's sake on an exposed steel chassis with lots of Voltage running around inside.
New film-and-foil coupling caps on the PC board. Some metal-film resistors where they were appropriate. New ceramic tubes sockets all around. Some new grounding.
I know this isn't what you asked for, but I wanted to hear what it sounded like in more-or-less its original configuration with a few updated parts.
I was not disappointed.