129 prepurchase questions

[cbdo]

Still love my 560SL but for a variety of reasons, I'm coming really close to switching to a 1998 SL500; a local dealer's selling the car for a local indie mechanic who owns it. Drove it--everything works perfectly, including the top, except for no air out the outside left dash vent. Only other issue I can find (before the mandatory professional prepurchase inspection) is a small crack in the center window of the soft top at one edge; the top itself, including headliner, is in excellent shape. Mileage is in the 40s and price $18K before any real dickering. As I said, I've always enjoyed my 107, but I couldn't help noticing that after I drove the 500, I somehow kept saying, "Dayumn!" As you all know, it's one hell of an automobile.

Two questions for you 129 cognoscenti: How bad is the usual fix for the single vent not working problem--semi-reasonable, or disassembly of the entire dash? And, I seem to recall reading that it's reasonable to replace just windows, not the whole top, on the 129 (unlike the 107); any experiences, and approximate costs?

Thanks for any insights!