I have recently got into a Manners PRS1, it came with a standard 13.5 LOP that is epoxied on. I'm 6'8" and I need around another 2" or so. I spoke with Manners on the phone, they are great by the way, and they said I would need to send it in and they would modify it for me. Unlike my McMillian, I can just remove the two screws in the buttplate and install spacers. Has anyone modified their Manners stock themselves for adding LOP?