One last finishing touch:
Earlier I'd noted that the rubber strain-relief sleeve out the base of the gun has aged and cracked, and had been unceremoniously taped back in place- with about 2-1/1 rolls of tape.
Well, my local Miller dealer was able to find me a replacement- the new ones being metal springs rather than rubber sleeves, but they fit into the old location just fine.
To install it, however, naturally one has to completely dismantle the entire gun:
After that, the new strain relief slips on, and one can reassemble the gun. (I'd noticed as I was taking this shot that I'd forgotten the clamp at the end of the hose- I did reinstall it.
And that's it. One well worn, high-mileage Tweco #2 MIG gun, fully freshened up and ready for another decade or two of use.