Thanks for the advice, everyone! I was able to complete the job yesterday... Somewhat time consuming but not too bad overall. Burned the gas as low as I dared and dropped the tank using a couple of floor jacks. Hit the pump access cover studs & nuts first with PB Blaster on Thursday. Got back to it again on Friday morning and hit them again with the acetone & ATF mix. No problems, thankfully. Weaseled the old pump assembly out & new one in. Reassembled and installed new fuel filler and vent hoses - the old Ford ones were really bad (copious black stuff on your hands if you dared to touch).
Refilled the tank with fresh gas & Stabil. Turns out there was still about 5 gallons in it. The old pump screen has rust particles in it, so I know there's some evil inside. Hopefully my keeping it full will minimize further developments...
The real test will be next season. The engine always started easily when cold, but would take a lot of cranking when hot. Keying it multiple times helped. My research pointed to a possibly weak fuel pump, so next trip we shall see if that was the culprit!
Steve & Carol
2000 Jayco 3230K Designer