Even though you have put a lot of work into designing the cocking handle to be similar to an AR's in location and function, I would suggest that a better location would be on the front left. Immediately above the support hand position.
Here is another thought - I assume that the stock clamps to the receiver rail, and is then secured at a second point. IF the basic unit could be designed to work with other pistols using the frame rail, and a second point appropriate for different designs, the market potential would be greatly enhanced.