Based on reference images and scaling from video, an MK23 mount based on a custom made mount seen on a Canadian YouTuber Hippo939's real steel MK23 video
. This mount is designed for the KSC / KWA MK23.
You will require one of these thumb screws, it comes in two thicknesses, slim
I personally have this item CNC in aluminium in the image shown above.
*Please note that the steel version was added as reuqested by a customer, this item was only tested on Shapeways in plastic so may require additional finishing to achieve similar fit due to tolerance difference when printed then cast in metal by Shapeways.