I can vouch for my replica, didn't know Abbey had worked on it as I was informed Dcash did it, but anyway, original or not it made sizeable gains and paired with the spacer is a WIN.
To identify between the MREV and Copy just looking at the plenum I don't think there's a difference, apart from the MREV2 will have 2 very smooth ports, where as the copies are the same but show signs of manual shaving of the ports. End result is the same.
ANYONE who is running a revup facelift should invest in the MREV and spacer, the sound increase is also nice too