A complication I have, which most others don't, is that we live in Hawaii. The PC is stored (indoors) in Tualatin Oregon, south of Portland. I had only been talking with rebuild shops in the Portland area, because we do two trips per year, spring and fall, of 6-8 weeks each. We don't want to have to hang around Portland while the seats were being recovered, so were asking shops if we could drop off the seats at the end of one trip and pick them up again at the beginning of our next trip. Nobody wanted to do that.
And if we have to "hang around" while the seats are being recovered, the cost of hotel/rental car/restaurants very quickly exceeds the cost difference for new replacement seats. When we're on the mainland, the PC is where we live. Much easier if you live on the mainland and can find a shop near where you live.
I'm going with the place in Lake Havasu City; new seats which will be a simple swap. I asked them about the issue Barry and Sue had posted... that the replacement seats they had looked into would not swivel. I'm speculating that shop maybe focused on seats for cars, vans and pickup trucks, and the issue might be their seatback didn't come up to the full vertical upright. The owner of this shop confirmed that is an issue. Seats that are slated for an F450, for instance, don't need to come to full upright (they don't swivel) and that is necessary for them to work in the PC swivel application. His seats all not only come to full upright, but go a little more, so the seatback is over the seat cushion during the swivel. He said he has never had an instance of their seats having that problem (and he's been in business since 1967.)
He said with our seat bases, all we need to do is remove the seat, take the slide off the bottom of the old seat, bolt it onto the new seat, and reinstall. There was no seat airbag in 2010 so we don't have that harness, and the seatbelt receptacle is attached to the base, not to the seat, so no issue with that harness. Bottom line, he said the swap is "very simple."
It was pure serendipity that we had already scheduled our fall trip to include a visit to the Grand Canyon, and go west from there, so that we will be passing by just 25 miles north of Lake Havasu.