Looking for a Sliding door roller

Hi,
I am trying to track down the correct roller for a sliding glass door in a manufactured home. The home is from 1981 and was made by Glen River Industries which is now out of business.
There is an AAMA sticker on the edge of the door, but is somewhat degraded. What we can get off of it is:
Code Mg1
Sgdb series 400/410
Mat 4.0x6.7 panels (ox)

I know that's not a lot to go on at all, but am really trying not to take the door apart to see the part, then put it together and then take it apart again when I find the part.

Thanks for any help you can give. If you need a picture of anything, I will do my best.
Charlie

Thanks for the quick response. We were able to get a couple of photos of the part while it is in the door. If you could help us at least identify what areas of it we need to measure in order to get a likely replacement or two, that would be a huge help. Again, thanks!
Charlie

Hi,
Thanks for the response. Now that I see the spots where I should be measuring, I am getting a lot closer. I don't think the one you recommended will work, but I don't know which are the most important measurements to fit. Here's what I have:
The width under the set screw is either 14/16" or 15/16" (it's hard to see)
The height at the end opposite that is 1-3/16"
The length is 2-1/4"
The dimple is (I think)11/16"
The wheel is (I'm pretty sure) 1-1/4"

Thanks for the continued help. We're getting close, I can feel it!