The screen rollers for my Milgard sliding glass door are making it difficult to slide the screen open. I can't seem to find this roller on your site. You'll see that the connecting point on my roller is an open "hook," while yours is a closed tab. Maybe the design has changed or there is an equivalent part. Let me know. The Milgard SO# is 2031046.001. I don't know if you need this; I just threw it in.
Do you sell this roller with an "open" hook back part?
Unfortunately, the manufacturer no longer makes this style roller with an "open" connecting point. The enclosed circle design is the only type currently made, presumably because it holds up better over the years without risk of detaching on accident. The downside to that is that it is a little more difficult to install, but the benefits are usually worth it.
You don't have to replace the door, just the corner. Our 95-020 is compatible with the rollers listed here.
You can very often reuse the corners, yes, but I don't know what your door has.
Before you buy anything, just make sure that the connection point between the 84-016 and your old roller are the same design. That will answer your question.