Roller for cabin door

It's a little hard to make out what you have here. Most of your photos show only the internal portion of the roller assembly, though I see you still do have an outer housing in your third photo. That's an important part of the assembly and it would be ideal to see the whole thing together. That also means the dimensions for the inner housing are not going to play a part in what replacement part you need.

From what I can see here, yours is similar in design to our 81-090. This may be what you need but look it over and see what you think.

Alternate image for 81-090