the '48-'51 is the same as my '48-'53, so you should be in good shape there. clean(don't spin with compressed air clean) and inspect the clutch bearing very well, ie, take the whole assembly to a bearing supplier for an inspection. they're generally helpful. and they are dirt-simple to work on. i did a few with no hands-on experience, but what a spooky feeling when i heard the needle bearings fall into the case, no idea where they came from, and didn't know about greazing them in for re-assembly. you sound willing. go for it
