Last week a woman dropped off her Brother XR53 at the Quilt Zoo. She said it worked fine it just needed a cleaning.
I picked it up, brought it home and finally was able to attend to it today. It wasn't that dirty.
I took off the needle plate and the face plate (if you can call it that). I brushed out the lint, took out the hook and cleaned under it and put it all back together. Total time, including stitch testing, just under an hour.
It is a full rotary hook, maybe an L bobbin or a 15. I couldn't tell since the one provided is plastic and seems a bit smaller than my metal class 15 bobbins.
The machine has many settings, I tried SS and ZZ and called it a day. Now to deliver it back to the Zoo so that the owner can pick it up.