replacement rollers

After much difficulty searching for the correct replacement rollers for my patio sliding door, I believe your model 81-090 is the closest I have found. My units have the number 138 stamped on the side, but I don't know if that is a properly definable number. The measured size matches perfectly except for the thickness, which your unit shows one half inch. While my unit is basically that width, it also has spacer strips attached, which bring the installed width to 13/16 of an inch. I could likely add some spacers on each side of your item to provide a workable setup, but it would be much more desirable if you might have a different model which is configured as described. Pleas advise.