Very early IJ Champion 12g.

[greenberg86]

Picked up an old Iver Johnson 12ga. shotgun. Believe it's a Champion, but name has worn off. The main spring on this one is a one piece flat spring that works with the trigger and hammer. Almost looks like an old clothes pin. Checked all the usual sources like, Numrich, Jack First, Bob's, Wisner's, Poppert's, Dixie Gun Works, Hoosier Gun Works, and Gunbroker with no luck. Anyone have one or know where I could get one??

 

[Dixie Gunsmithing]

That is the old style single barrel, as the Champion has a coil hammer spring.

Is this it:

https://www.gunpartscorp.com/Products/480140.htm

 

[greenberg86]

Is saw that and now the pic you sent of Numrich replacement. mine is similar, but mine has a ring formed at the top which fits into a socket in the receiver to hold it in place. I was going to call Numrich in the morning to check the length and if it's an aftermarket made replacement.