This is the info Gunnar emailed me. I don't think he'll mind me passing it along:
And here's shipping info...
Shipping:
Call 1-800-731-4000 - ask for a short-term ATT to get your gun to the post office for shipment to me for repair. They may want my dealer license number – (*better call Gunnar for that- OH), and they will need the street address of your post office. Include your PAL number and the cert. number with the gun (as well as full address of course). Pack up securely (they want the guns locked so nylon Zip-Ties work well), ship to me by Canada Post Ground (new Canada Post regulations, no firearms to travel by air), Shipping address is:
AMP
PO Box (*best to call for this also - OH)