Can't find a replacement for these old window rollers. They're 9/16" stainless wheels. None of the ones commonly available fit because its square hole (not a channel) and the screw is above the wheel, not on the side.
Casey from SWISCO responded:
July 30, 2021
Hello,
Your roller looks like a dead ringer for our 87-186. Take a look and see how the dimensions compare to yours. Thanks for posting!