Awesome job. I have made Kydex sheethes and Magazine Holders in the past and am looking to get back into it. The materials are extremely cheep. Instead of standing on it I used the wood and foam trick but used clamps and vice grips to press the two boards together. Then used a hair dryer to heat the finnished product to forn the "wings" to create a tighter fit to the body.
Also love the M&P. I have one I set up and replaced all the innards with the APEX setup. Once I stop being lave iI'm going to do the AEK trigger on it.