sm420 broken

[67GMC3/4]

Well truck has sat while I finished school and decided to get it up and going last night. I swapped a new battery into it and got it going and hit some trails by my house kinda just to get the fliuids going in it. Well it didnt last too long was messing around climbing some hills and had to get on the pedal to push me up and after i hit the top i heard a loud cluncking noise, then felt the shifter start to kick around in the cab.Decided i was better of puttin it home and it did good still ran, so i figured it was maybe a linkage problem or something non catastrophic lol. I pulled the side cover on the truck and noticed that magnet inside not only had some chunks of metal but had a few teeth in her. now this leads to my next question anyone here familiar with these and anyone rebuild them before ? it looks like a simple one to do. Next question is the master kit that novak sells to rebuild it, does it include all the gears ?