Yeah, AirsoftNY is one of those highly skilled customers and has done some crazy stuff using Escort internals (For those who don't know: Escort is the small japanese manufacturer, who has built the internals for Shoei's MP44 and MG42 GBBs. They had some very promising GBBs but after serious mismanagement and being rude to customers they pretty much went down the drain.).
Check out his
Youtube Channel, he has also built an RPD and an M2 (!!!).