The next step was kinda tricky. The four, Phillips-head machine screws holding the metal ring (and the bowl) in place had not been removed in many years and were virtually frozen in place. So I gave each screw a shot of Kano Laboratories Aero Kroil (www.kanolabs.com), the fastest, most trustworthy penetrating oil I know of, waited a minute or two, and then used an appropriately sized, ratchet-equipped Phillips-head screwdriver (and plenty of pressure) to back the screws out. They came away rather satisfyingly, I must say.
When I removed the metal ring it was quickly obvious that the gasket that seals the metal ring and bowl to the canister bottom was the problem. As luck would have it, I’d already purchased a new one (shown in my fingers above), along with a whole bunch of other paraphernalia that came in a $56 “Gasket Pack,” as well as a new drain assembly for $55.97 from Parker Racor. Yeah, I first tried to buy just the gasket and the drain assembly, but no dice. I had to buy the rest of the stuff as well. But hey, at least the extra lid gaskets (black) and the little gaskets that seal the T-handle base (reddish orange) that came in the Gasket Pack may come in handy some day.