steele rubber products makes seals in all profiles
especially if your seals are 25 years old
a window seal is easy to replace, and the glass is re-seated into the seal using a piece of cord and grease- like a 10 minute job for a novice
youtube for a diy lesson or an old timey glass shop will do it for you
if my windows went, i'd replace with a piece of acrylic.
easily cut with a rotozip, dremel or jigsaw.
panels cheap at home depot, rona, home hardware etc