Window regulator question

[68Timber]

I've got both of mine out and have cleaned them up in the parts washer and used a brass brush on the rollers trying to free them, I've got two on each side that don't turn so well anymore. Otherwise the regulators are fine. Any tips on freeing the little buggers up? Or should I just replace them? I'd probably replace the whole assembly rather than try riveting new rollers on. Or am I not holding my mouth right? Any wisdom here is greatly appreciated.