Nice review and great pics! Just a couple of questions for you...
As you have that nice M/Op MP5 to hand, have you been able to see its (genuine?) stock and fore-end will fit the .22LR clone?the fore grip feels like it is off a toy, (and most likely is, since the company originated from the airsoft market). The same goes for the plastic stock.
Presumably you fitted the SUIT sight from the M/Op gun. This looks to have a particularly high sight line. Have you tried the same base with a conventional scope or reflex sight and rings?as we found out, [optics] mount very high on the MP5 platform, so you would want some kind of cheek piece.
That's it! Thanks for posting this!