I don't have either part (and a quick look at the usual suspects, no joy), but for clarification are you talking about the recoil spring plug at the front of the frame, or the pin at the back of the frame that holds the hammer, sear and disconnector spring in place? I'm guessing the recoil spring plug because that can break the retaining leg(s) pretty easily.
You might try contacting Sarco, they have a ton of parts that aren't listed on their website.
Thanks for the leads gentlemen. The people at Sarco were super friendly and helpfull and called me back right away alas no parts for the Hahn. There seems to be a good number of these guns around I'm surprised there are not really any parts available. Think I've pretty much check all the net has to offer.
PS: yes its the front thimble looking piece that keeps the main spring from shooting out when you remove the takedown wedge.