One of the best (and cheapest) improvements I made to my '46 was to replace the worn shifter pin that goes in the ball of the shifter that moves the shift forks. Mine was super worn and I replaced it and that tightened up my shifting substantially. I used part of a drill bit (the smooth part) for a replacement pin. I might have seen the idea from an article on Jim Carter's web site where the sell the kit. I didn't need any of the kit parts but the pin which is not included was where my problem was.
