I found the round glass lens's with stop for cheap just like org. Its at a web sight called lowbrowcustoms $ 20.00 plus shipping. I have been looking for a while and thought i would pass it along. Hope this helps some one
They are very cool guys to deal with. Tyler puts together some cool stuff including the current twin-engine triumph for the flats. I am pretty sure he can be found on the sister site... FYI - he's got a ton of parts for making some period correct bikes. much of that can be carried over to this side (cloth wire and such)
All that taillamp stuff is available from any one of the 100s of Model A Ford parts sellers across North America at better prices than that. The lenses are/were American made by a glass company in Ohio.