Search in the classifieds, there's a guy in there that makes a secure T-post mount for a camera in the camera security enclosure. I have 3 of 'em.
M&P-10+AAC Cyclone - Kel-Tec RFB+Griffin Sportsman Ultra Light 300
ATN OTS 336-50mm 9hz Thermal Monocular
ATN NVM14 NV Monocular