Here is a used collapsible stock with recoil spring and guide assembly. This unit functions perfectly, shows some slight wear. It has been painted. I'm not able to find any HK markings at all, priced accordingly. $125, price includes USPS Priority shipping. Paypal (+3%) or USPS money order. Can provide more pics on request, I still can't figure out how to post pics here. Email firstname.lastname@example.org with questions/requests. Would consider auto BCG as trade.