As in another recent thread, I talked about shackles and finding springs I thought I had lost. It seems I still need 2 more. How does one go about buying springsof a specific length? What material do they need to be? etc.I did find this site, but the data required was like egyptian to me:
link
For those interested, here is a pic of the pedals, they are slightly different than the plans.

I am trying to source the spring below:

The eye to eye distance is 2 13/16".
I assuming shackles are needed either end too?
This is a pic from the 70's plans. The 90's plans have the spring going into the corner diagonally.