I just read an article about an effort to compile the locations that have or did have Tiffany windows. It is a giant challenge but certainly a worthy one.
http://www.cambridge2000.com/tiffany/index.html is the web site. It is very well done, and you can look up by city, date, designer, category, status etc. They also give a confidence rating which says how certain the piece is truly a Tiffany Studio piece.
For example, Maine has 19 sites and 10 of those sites have something still there! How exciting. Two of those sites are in Augusta, Maine!
The South Parish Congregational Church (which I have visited) has had 9 items, 8 of which are still there! (Can you tell how excited I am by the number of exclamation points I am using?)
All these photos were taken by Wayne Boucher. These are all on the site that we share the link above. I encourage you to go to the site. My copied (with permission) pictures do not do them justice. If you go to the site you can click on them and they will enlarge. They are nothing short of breath taking!
St. Mark’s Episcopal Church has one. This is not an active church and there is not a picture.