I sent my '42 Sprague drive off for rebuilding to:
They claim a 95% success rate. It has to be de-crimped in order to replace the rollers (which may be worn) and the springs (which may have weakened over the years through heat exposure and usage), and maybe the innards have to be machined smooth again. How they undo the crimping is always a mystery to me.  The Sprague drive (Autolite MZ3158) is such a rare part. It only is used on '41-'42 Crosleys and there's no interchange listed.

I took the Sprague clutch off the starter in order to send it.  Carl Sr. at Oklahoma Starter Drive said the springs had gotten weak, and he replaced them and the rollers as well. Also he cleaned up the inside of the drum. He found that the shaft bushing had worn oval, and called me to 'mike' the shaft so he could machine a new bushing for it, and he did.