Mark,
As Mike mentioned, the original system of "guide jaws" is a bit difficult to maintain. I recently re-conditioned both doors/windows on my 280 SL. On the passenger door, the original guide jaw system was in good shape, but on the driver's door (which gets the most use) the guide jaw system needed alot of work. At the suggestion of Ray Paul at Bud's Benz, I tried his "felt channel" system. This has the advantage of no maintenence, less adjustment, lower weight and probably less cost. Not only did the conversion go very easily, but the window works better than ever. No rattles, very good alignment, and the secure feeling that I will probably never have to mess with it again. I believe, as does Ray Paul, that this is an improvement over the original system. Even if you show your Pagoda at a Concourse event,this is one non-original item that no judge will ever know about. Give Ray Paul a call. He'll be happy to descibe the system to you.