Sliding window rollers

I'm looking for replacement rollers for my sliding window. These have a metal body and plastic wheels. I think these are the original rollers from when the building was built in 1976.

Couldn't find a brand name on the aluminum frame. The glass says Arm-r-clad EE Glass Lad.

Looks like the rollers have been frozen for a long time and the window frame track sawed into the plastic wheels. There's two sets of rollers per window. Each set has two wheels.

Are you able to help identify a replacement? Thanks