[walker]

Might try going to a junkyard to see the linkage. Those linkages are notorious for hanging up. The '64 I learned to drive in was hell, had to get out of the truck and wiggle the linkage to free them up usually at a stop light. I seem to remember that they were not that difficult to rebuild by welding up the worn spots, and lubing everthing real well. Mine never kicked out of gear though, just hung up. You may have a syncro problem, try changing the gear oil, or try a lighter gear oil. The newer manuals use motor oil, or auto trans fluid. Good luck, sorry I can't be more help as I have an auto in my '67 now.