This is a V Spring for the top lever on a 1889 Remington Hammer Gun 12ga. This is impossible to find, for me anyway, so I ended up jumping in to fabricate one. Here is after the first day of filing, grinding, bending:
Fun stuff and I know what its like(I have made a few oddball springs). As you likely know make sure after you heat treat it to draw it back so your hard work does not crack or break.
Do you have a website to find instructions for heat treating it to be springy? It does not look like spring steel and I thought spring steel was an alloy but it looks like you are going to heat treat it to be springy.
I used a retaining clip from a hitch pin, I think it will be springy enough. I don't know what spring steel looks like, so I don't know if this looks right or not?
I am going to heat treat it, and then draw it back.
While you are heat treating you might want to anneal the original and weld it back together and re-heat treat it too. I did this to an M1 Garand clip just to play around. It worked quite well.