The retainer is made thicker to allow more meat and tolerance adjusted for nylock nuts
The cap & capshort is optimized for M4 screws heads that I have in possession. The internal pocket for a M4 nut is also adjusted for tolerance.
The lock is made 1mm thicker to decrease chances of snapping during assembly
The carrier has had two hole bevels removed as they tend to bind my springs, the geared wheel is also made longer for more positive engagement
The rail has had the geared wheel made longer for positive engagement
The helmet mount has had the nut pockets adjusted in tolerance for ASA. The geared wheel is also made longer for positive engagement
I wasn't sure how the original's spring mechanism was to be assembled, so I made my best guess and optimized it's assembly to the components I've had on hand.