Uncut: I had an HK4 .380 with the .22 conversion kit. It was partially gold plated and a 100 year (1971) commemorative to Harrington & Richardson (who used to be Heckler & Koch's importer). It was serial number 00005.
It was a neat little gun but it had an atrocious trigger pull, both DA and SA. And that heel magazine release was not the best.
I brought it to a gun show and a guy who liked low serial number guns asked me if I wanted to trade. I went over to his table and saw the PP Sport. I traded him the HK4 and a little bit of money and walked away with the PP Sport. That was about 22 years ago. I think I got the better end of the deal!