Side mount, front roller bracket

I thought it was a Shrock cabinet, but they won't admit to it. . Right and left side brackets that have 2 rollers on them. 7" long and about 3" height at the front. must have been made in the '80s
When you pull the drawer open, after a couple of inches it drops down. Not out, just down. It has regular side rails, and just under an inch roller.

Do I just need new rollers? I have a couple of drawers that the rollers are about gone
I can get a more accurate measurement on the roller with current wear, but the track is just under an inch also.