67 delmont conv.

I am hoping someone can help me with some information!
I have a 67 Delmont 88 Convertible with the Tilt & Travel Steering Mast.
The turn signal lever, works great on the left hand activation. Click it down and it stays in place until you go around the corner and then it returns to center. When activating it up for the right turn signal it does not stay. It just falls down to the center position. i have owned the car for 11 years and have been driving it like that for all those years. I just hold it up and make the turn keeping pressure on the lever. I live in Seattle and only drive it with the top down so it is only about 5 months out of the year, but enough is enough! I have had this problem with other cars and it is the Cancellation Cam. I have not had this model apart and I have noticed in the schematic alot of springs. I have changed the cancellation cams on quite a few cars. I have been looking on Ebay for at least 6 years hoping the parts may come up. No luck. I believe there was 2 styles of Turn Signal switches used in this steering hub with tilt & travel.

I am hoping someone may have some knowledge to help me out, either to keep me from destroying something when I tear into it, or to help me solve the problem! Thanks for any help you can give me.

Scott