For my M11/9 smg...
I have two MPA (Masterpiece Arms)/RPB sidecocking uppers... one w/ the rail & one w/o. I have a Tasco Optima dot sight mounted on the rail. This sight is discontinued, but the Doctor sight should work even better. Even if you don't get a dot sight... the rail-less version gives a great, unobstructed sight picture
The FAL-type charging handle is NOT spring loaded. Some users have reported light primer strikes on hard primers when not returning the handle to its full forward position manually; although I have never experienced this phenomenon.
The finish is a slightly darker, smoother park than the Cobray original upper... but it's a close match. Stoney Creek Armory makes several variations of this upper... including K-type grips, etc.
I believe that this upper is all original & not reworked.
I love it!
Note... that if you decide to use a side-folding stock... you will need to find one that clears either the charging handle or the ejection port. Since this handle is non-reciprocating like an UZI... you don't have to worry about extended cocking knobs turning in their respective slots... splaying the cocking slot!
It's a high quality unit!