Sunroom window rollers
I'm sorry to say that we don't sell this size, either. The largest roller we sell in this design profile is our 87-035, but this still falls short of your measurements. The wheel is also flat instead of concave, like yours. I don't think it's worth considering.
We do sell replacement wheels for sliding window rollers. Our 87-133 is 11/16" in diameter and appears to be the closest we can offer. This also has a 3/16" inner diameter and is 9/32" thick (not counting the axle). Look it over and see if you think you could use this to repair the original assembly.
Honestly, I'm not surprised to hear that this is for a sunroom. Sunroom hardware is very odd compared to most residential window/door repair parts, and more relevantly they aren't being made like they used to. Just something to keep in mind as you move forward with this project. They're a real pain.
