For a buyer that is knowledgable about Rollei's the fact that Fleenor has serviced a camera can definitely be a big plus. Although I don't know that anyone can say for certain exactly how much more one could ask for such a camera. As you've noted, prices can be all over the map at any given time.
My feeling is, if Harry's doing the work you are going to get back a Rollei that functions exactly as it should. Possibly even better than it ever did before, even when new. And as an owner of a 3.5F Type 1, I strongly suggest you hang on to it. There were far fewer of the Type 1's made than any of the other F models so it has a bit more exclusivity (not to say that's extremely important, just interesting). I happen to like the Type 1's interlocking aperture/shutter speed control arrangement (somewhat like the EV system on Hasselblad/Zeiss lenses). Not everyone does.
In any case, you'll soon have back in your hands a correctly functioning Rollei. Enjoy!