This stated that it is an Alliance 1002A sliding door roller. This has 1 1/2 inch spacing with a 7/8 inch roller and a 1/2 inch offset. You were recommended to me by Ace on 63rd and Main in Downers Grove, IL
Tom from SWISCO responded:
January 26, 2016
Please see our 23-025. It's not an exact match but it seems to be the closest available part we have. Look it over and tell me if you agree.