I have a drive from 2008 that is well worn. It has the set screw masts. It would be great to refurbish this drive with 2015 parts.
What are my chances?
Your chances should be excellent. You'll need new threaded masts in addition to the kit and new cables if you have the old style drums. Take a look at your 3 shafts for wear. Typically they wear on one side so if you see that they are worn but don't want the additional expense of replacing them, you can flip them to transfer the load on the unworn side.
Easily done except for the idler shaft where you would have to file a new notch on the opposite end/side for the lock screw. Don't overtighten and use Locktite Blue on these Allen screws or you'll risk cracking the spine or screws backing out.