'67 Notchback Barracuda Window Regulators

There are replacement parts, plastic rollers and such, for front and rear regulators. There are ways to DIY renew a worn regulator with donor parts from other later model less worn regulators.
Without searching I'll just guess that entire new regulators for same year model Camaro and Mustang are available. Maybe Chrysler e-bodies too. I'll guess deep pockets are required for any that are available.
Good luck