Check with major glass shops in your area -- they may be pulling out old
jalousie windows on houses to replace then with more energy-efficient
windows.
Yes, they will be the wrong size, but the width can be adjusted by shortening the glass louvers, and the height by keeping only the number of louvers you need.
I got several used jalousie
windows from our local glass shop for free! They were happy to give them to me because otherwise they would have to pay dump fees.