If you check out the diagram articap posted, look at item 'T'. That's your ramrod retaining spring.
Not on a GPR.
The OP correctly identified the parts (No. 1 & 2) in the diagram in the link in his original post. If the underrib rail does not have a screw hole to mount it you'll either need to drill and tap one or get a new rail. Call Lyman and talk to them.