I didn't realize that REY was inquiring about a REAL HK product that was purchased overseas. If this is, in fact, a real HK, your local HK distributors should be able to help you.
I can tell you from first hand experience that HK will not sell supplies to guys that have converted guns here in the US. I'm a huge HK fan and have several Registered Receiver HK guns... but they all started life off as the semi gun. HK will not honor any warranty, or perform any work on these guns. Or sell you replacement parts.
danbrew :->