Rusty, have you considered getting helical gears? I bet someone makes the sizes you'd want. If worse comes to worse, you could probably get some made. (Probably cost a lot though) If you cut them the right direction, I bet you could get away from even needing a cam button. The forces acting on the gears could be set so it's a complete non-issue.
https://gearmotions.com/helical-gears-vs-spur-gears/
