One of a pair of interesting, very heavy windows i found

i watched these windows being removed from a very old mexican restaurant in my neighborhood last night and i asked the workers who were replacing them w/ new plasticky ones if i could have the old ones and they said 'por supuesto', so i ran home and got my car and took them home. there are two exactly alike - about 4 ft by 4 ft and each weighs at least 150-170 lbs. made of steel and tempered glass and they many, many years of paint coats on. what are these windows called and when are they from? my guess is 1920s-30s, but who knows?

why is cw only allowing me to load one photo? it doesn't accept any more that. grrr!!'

what category should i put this under?