They had their explanation for the gap. I guess he figured that I still didn't see the point of the large gap.
The next day the company engineer called me, Mark 23 with adapter installed in hand, and he had a very technical explanation for not being flush with the frame, while acknowledging it could be closer. He was very understanding of the asthetic issue, and offered a refund or other product without being asked.
I'm keeping mine, on the gun, and the gap no longer concerns me at all.
As far as marring If attached and removed, I can see that happening, as it is fit quite snug on the hk rail. A little bar soap like lubing a screen door track allows it to slide on and off more gently.
In all other aspects, it's a quality product.
Sent from my SAMSUNG-SM-G930A using Tapatalk