Sliding screen patio door

Your roller looks like a match for our 84-091, but take note that the overall thickness of the housing is 3/8". As long as yours is also 3/8" then I believe this will work for you.

Thank you for clarifying. In this industry, the term "roller assembly" usually just refers to just the roller itself. The corner you're asking for is technically a different part, hence my confusion. 

Unfortunately, we don't have a replacement for that corner. If I remember correctly, this was an old part used out of Canada a long time ago. However I haven't seen it in years and I'm not sure who would still carry it. If I were you, I would contact a local hardware store who deals in screen doors and replacement screen door hardware. Try to avoid big box stores and instead try to find a mom and pop kind of shop. They may have some of these in stock still, or could at least point you in the right direction.