I have some windows that I need replacement rollers for. The part I need is almost identical to your part #87-189, but only has a single nylon wheel vs the 2 brass wheels as your part has. Can this be used in place of the part I am looking for? The original part was a P.E. Delmar Model 4680 roller.
Paul from SWISCO responded:
November 27, 2013
As long as the measurements of the nylon housing match, then the 87-189 should still work. You could even remove one of the wheels to match your old one.