After cleaning up the surface rust and corrosion I flushed the gear box a couple times and filtered the solvents to see what came out and it wasn’t bad. I popped the shifter off the top to inspect the gearbox and repair the sloppy shifter which was in grave need of new bushings and proper adjustment, (the adjuster screw under the shifter was really out of wack). There was no visible sign of excessive wear, damaged teeth etc. New seals, gaskets, nylon washers for the shifter and a little paint got it done….