Credit: Info from Jim Schatz G3kurz HKPro "These were special ordered these from HK GmbH in the early 1990's - both MP5 and G3 versions - for student purchase, and to get a set for the HK Inc. Gray Room (had to order a minimum qty!). They are made, like the cut-away weapons, by machiniest apprentices at HK GmbH and must be made from "raw" or unhardened parts so they take both time and special effort"