Reverse stretch is a K carrier and bolt heads are the same. I believe the LP's are #16 on a RS. What I have is a full size Mp5 group, although the LP and BH would work.What are you asking for it? I don't necessarily need one but good to have a spare. Also is it for the reverse stretch model?
I have an FAB defense stock for an AK47 and it's quality! So I'm sure these are good to go.though it is not as sexy as the HK stock, and it is polymer, it is a very good stock at a reasonable price. There is not any fit issues.