@MattL go to an inline skate store. They'll have a box of spare buckles out back you can get cheap. I did it for my R-style years ago and no problem.
Also my mounts have a little rust in there but still are ok. Spray in some WD-40, screw the screws in and out a few times to make sure thread is still good and re-mount. I do this as a matter of maintenance a couple of times a season.