I might do the sensor array from a Coyote - I just found the operator manual for in the book stash, and its chock full of line drawings of all the fiddly bits. The reason I was going with a Fennek mast set was that I wanted whatever object that sat on top of the mast, could be retracted into the hull. The limiting factor is the size of the hatch opening you can see where the base of the tube is. A Coyote sensor would have to be added manually by the crew. I may just scratch a Fennek-ish module. Its a box with an arm and a couple lenses. More or less.
For sure when the mast is raised there would be an electronic lock-out to elevate the gun barrel and clear the mast. The logic being if the recce crew finds themselves having to fire the gun when the mast is up, something has gone drastically wrong!
I'm also going to add some stabilizer legs where the marine drive would normally go. Something like what you would find on a back-hoe, or maybe like the Husky ARV. When the wheels are on, the vehicle looks like it would be a tail-sitter, but the fact is there is a lot of engine mass over the front axle that I think would make this a nicely balanced 4x4.
The stack of discs wasn't turned. Just CA'd together and shaped with a metal file & Mk 1 eyeball.