that's funny I did the same thing but was too impatient to keep looking to find pics with the springs.
Spring Type Compression
Material Steel
Wire size .105
Od .525
Free Length .835
Number of coils 6
Ends ground
i
Check this set of springs. I need to measure the deflection to see if one of these or another is a better fit. I suspect that SS is the right material, especially if we are going to have to hunt for the right spring with trial and error a bit.