pair of red glass railroad crossing gate light lenses

Found at a random flea market somewhere awhile ago, this pair of red glass fresnel-type lenses were made for use in old style warning light fixtures on railroad crossing gates -- the little lights mounted to the gate arm itself. (and 'back in the day', before plastic then LED's came along to replace them 'more efficiently'...) They're 3-1/4" across the open ends (w/ ground edges) and about 3-3/4" across overall, and 3-1/4" tall. No maker's marks on them, just mold seams on each side and the word "TOP" at 3 places around the upper rim.