I got mine from Stoddard's.
If you use the CMC (Signal-Stat) base (which expects to use a taller lens) you may have to get some small, low-profile bulbs ( TS97A for amber ) to fit inside of the lenses. I also used a couple of lens gaskets made from 1/8" thick, closed-cell foam (just a round gasket shape) to push the lens out from the base a bit so the bezel fit properly and the lens was positioned at the right height. You'll see when you try to fit everything.....