here's the parts list i compiled, for a pistol upper only, NOT 922 compliant:
this list is compiled from HKParts, but many of these items are available from several sources:
Cocking Tube & Support Set for HK MP5K & SP89
HK Cocking Tube Hanger Clip
HK51K Barrel Cold Hammer Forged
HK MP5, MP5K Cocking Handle
Front Sight Tower, Cocking Handle Pin HK German
MP5, MP5K Cocking Support Detent
HK German MP5, MP5K Cocking Tube Support Spring
Flat With Weldment Set HK 91, G3, PTR, CETME
HK Triple Frame Front Sight Tower - HK 91
SORRY, FORGOT TO INCLUDE VERY IMPORTANT #18 LP
i am using a donor bcg and will have a standard carrier, cut down as part of the build.
i plan to use a donor lower off one of my rifles. i am sending this to Jeff for assembly, i'm not yet sure "how it works" for the spring and buffer. also i want to do a GRS so i have not included rear sight parts.
also a quick plug for Jeff, he has done several build/rebuilds for me. he is a model of great customer service and his builds run great!!