Here is a photo of the springs that I used on the Road Runner.
View attachment 1715314846
They are 1" in diameter and the wire is 1/8".
You may be able to find some at a Good Oldtime Hardware store.
If you want these I will take $10 for the springs and $10 to cover the U.S. Postal Priority shipping and 25 mile round trip to the post office.
Herb