Tom your reply is kind of vague, "I don’t think that I’ve ever seen a spring that contacts the “J” spring and the cocking plate. I think that spring is putting enough tension on the cocking plate to keep it from moving and hindering it from opening".

The spring on the early guns was a metal spring that put pressure on the "J" spring knuckle and the other end put pressure on the extractor activator. It was held in place with a machine screw in the center. There is no spring on the cocking plate, it is held in place by a short 4-40 screw that is countersunk in the cocking plate.
You can make a spring from a hacksaw blade.