I recently bought a Perkeo MF folder from Jurgen (A.K.A. certo6) off of eBay. It had a few minor issues. He very accurately described them, and there were no surprises at all when I got the camera. The Shutter he CLA'd is nice and snappy, and the bellows looks perfect. Even better, he had offered it at a very reasonable price.
Everything about the transaction was well done and I'm left a very satisfied customer.
After having bought many Many folders over the years, I can already tell, this is the one I have been waiting for. If only it had strap lugs . . .
If anyone is in the market for an old folder, I'd highly recommend starting with Jurgen. I could have saved myself a lot of time and money in the search for a usable old folder. Even if he doesn't have what you're looking for at the moment, it's probably worth the wait.