Customs 1948 Chrysler Convertible Top Motors

On one of my 1948 Chrysler convertibles I have misplaced the "drive" springs that go between the 6 Volt motor which has has a 5/16" shaft. that shaft has a slot cut in it across the diameter of the shaft.
The worm gear assembly also has a slot cut in it that this spring will fit in to so the motor will drive the worm gear to raise and lower the convertible top.

Anyone know about a spring like this?

What would I call it to search for one?

I have made a replacement for it by using a 1/2" steel tube which I slotted and drove a piece of steel in it and welded it to the tube and cut a 1/2" piece off to use for my "drive" piece.

Should be OK but I am curious to see if this spring is used in another application.

Pictures coming after update of IPhone

Don

 

Try Hydro-E-Lectric

 

Thanks, I sent them a email.
No help as far as their web page and the years listed.

 

Also try Convertible Service.