Air conditioner box

[Dan Wing]

I bought my car in Florida a year and a half ago, and it fogged up in cool weather and smelled musty. The mechanic found an oil bottle wedged down in the air conditioner box to hold the recirc door closed, and after it was removed the car dried out. This winter I noticed it did not defog as well as expected with passengers in the car and a different mechanic has found that the air motor for the outer door (slide?) on the box has been broken off of its mounting in such a way that it "cannot" be reattached. Apparently the air motor itself is OK (though disconnected and the lines are plugged) and the door is OK, but the mounting on the box is irretrievably broken so the door cannot work. Mechanic estimates hundreds of dollars to replace box, even if I find one (disconnect air conditioner, replace box, R-134 conversion, replace components). 

Anyone seen this situation? Anyone done a less expensive fix? Mechanic says climate control probably confused by constantly open outer door, but perhaps that is not so big a problem and I can just leave it, or perhaps fix the door in a half-open position? I live in Vermont (cold winter, not too hot in summer), so could I just fix the door in position seasonally? If so, what would the positions be? What is the consequence of this door not working?

Lastly, does anyone have a good air conditioner box to sell me, if I go that route??

Dan Wing