1964 Turn Signal Switch - Thoughts Appreciated

[Nevada51]

My turn signal switch may need replacing, but I first wanted to see if anyone can tell me if anything is missing from it (springs?) - see pics below (apologies if they look huge!).

The switch turns both signals on as it should, but the arm wont stay up for the right hand turn, and sometimes the left turn goes on when it shouldn't - so basically the weight of the arm is working against it.

I've tightened the brass looking screw at the rear of the switch which seems to have helped, but is it broken/missing anything??







Appreciate any thoughts.

Thanks
Cam