OK, I may come to regret this decision but I ended up buying the 1989 K100LT that sat for 17 years without being ridden. When I went to the seller's house he ended up backing the bike out of his garage and I saw that the garage was air conditioned and humidity controlled. The brakes still worked. Gas still sloshed around the tank after 17 years. And the seller dropped his price by $1000, which made this bike seem like not such a big gamble.
Once I find a site to host my photos, I'll post some pix of it. It's in my garage now along with its saddlebags, top box, a backrest with its own little luggage rack, a BMW-branded tank bag, and a really nice dust cover.
So, now I get to drain all the fluids, replace all the rubber hoses, replace both tires (which are Metzler's from 20 years ago), replace the battery, replace the fuel filter and perhaps the fuel pump, and then see if the injectors still inject.
Should be an adventure....
Scott