I see a company now offering tso'ed mounts on a UK advertising and news email letter
My spidey senses are tingling at this. The FAA website does not list any TSOs for camera or mounts, so I'm not sure that there is even a category for TSO approval of a mount, much less any TSOs have been issued by the FAA for camera mounts.
That said, the fact that a TSO has been issued for a piece of equipment does not convey authority to install, that still requires "data", which may be a type design OEM TCDS, an STC, or other data acceptable for the installation. The very easy way to understand this is to consider the tire: A 6.00 - 6 tire is approved on many GA aircraft, in both main and nose wheel applications (and I speculate probably a tailwheel on larger types). These tires come in different ply ratings, and are TSO'd. But the fact that a 6.00 - 6, 4 ply is a TSO'd tire does not convey approval to install in an application which specifies a 6.00 - 6, 6 ply, That would require an STC, as well as the TSO'd tire.
So before you start attaching cameras to an aircraft, make sure a suitably rated aircraft mechanic is in agreement with the installation.
Should you have a camera (or more) one your aircraft, remember, you're there to fly the plane, not be a movie star. Focus your attention on safe flying, rather than flying for the camera. People have been known to do dumb things when they thought that a camera was recording.