I just refinished the panels in my 79 300 with SEM. Worked great but make sure you follow their directions. You need the adhesion promoter to make the paint adhere to the plastic. You can use their cleaner but I just used Methyl Hydrate.
If the motors still turn but the pucks have disintergrated try this fix:
How to rebuild Chrysler Power Window motor clutch assembly
As for the broken guide that I have no answer for but someone here will. The spring can be seperated from the regulator. You shouldn’t need a new one just the spring.