I second what they said. John has always squared me away with what I was looking for from him. He has quite an extensive reproduction line and the new stuff is just as good as NOS. I have no complaints about the others either, all are good sources and have good customer service in my opinion.
I also shop around a bit. The vendors listed: AB Linn, VPW, Adirondack, and the others are all excellent sources for parts. But shop around, some are better priced than others. I also do google searches sometimes for parts and have found parts in out of the way sites. Some surplus stores also carry parts that have been under priced compared to many M37 vendors.
If it can wait, like an upcoming project you are waiting for summer or an indoor winter project, I find the seasonal MV swap meets are the best places to find stuff for (usually) less than most of the mainstream vendors. Nothing like being able to see and feel the part you are considering on buying.