My gas pedal just snapped

OK, I got a replacement gas pedal (had cracked and was heli-arc welded) from Glen Pascal. I had a little bit of a problem getting that c-clip off put finally managed and got the new pedal on. Now the problem was trying to get that fun spring back on. I tried several times with no luck and then the last time it slipped and went "sproing"
and I lost it. Not sure where it went, so I need a replacement for that too. Anyone know
what (how are springs measured?) I should replace it with? Thanks again for everyones help here. This is a great place for tech support.

The pedal is in fact, cast aluminum, and can be easily TIG-welded for $10-20. This seems to happen to cars in which the throttle cable is adjusted short so the cable acts as the pedal stop (but not for long...)FYI, the cable length can be adjusted about 1/2" at both ends- doesn't look like a clevis but there are actually two.

So, should there be some sort of spot for the spring to attach to? In the broken pedal there is a small hole drilled in it to hold the spring. I think this lead to the failure by weakening the arm. Should the spring just go around the shaft or should there be something added to the shaft (small piece welded on to hold the spring end)? Thanks.