I am restoring a '66 Lemans 326.  Where do I find parts such as chrome door trims, exterior door handles and windshields?  

I am happy to hear that you are working on a 66 Lemans. I hope you keep it as one. I have found that most of the trim can be found by searching on E-bay or from the various restoration supply companies like Ames or OGP. I can give you one very valuable bit of advice, not all of the parts are cross compatible with a 67 body and the 4 doors are slightly different than the 2 doors. Example is that the glass on a 2dr is different than the 4 door but the glass on the 67 and 66 are compatible. The trunk lid trim and front grilles are different but the hood, doors and front fenders are compatible. I have 3 67 Lemans in process right now and I have been using forums like this to help me find the parts i need and i search E-bay alot. I have some 66 trim and sheet metal if you want to send me a E-mail i can tell you want i have. As far as the windshields go I am still working on that myself. Good luck.  

Depends on how serious of a resto you are doing. Most any auto glass shop can get you one andsome can get you a correct date stamped one for an additional $100 and about 2 weeks wait. I think Year One has these also. These windsheilds and side glass are common to most all of the GM "A" bodies of the era. Door handles can be had from any number of resto catalogs. For my money Ames is a good company to do business with, very freindly knowledgeable and helpful folks. The door trim maybe another thing, E-bay maybe the answer there but buyer beware.