Chuck, I'd forgo the potentially messy spray and use a 2" strip of industrial level sticky back Velcro, putting some reinforcing stitches in the side that goes on the leather. I bought a 30 foot roll of the stuff for all kinds of household things like affixing removable pouches in my camper to hanging my RH Designs Process Master-2 and Paper Flasher on the wall of my darkroom, it has been worth the effort.
Leather is inherently porous so I think that even though it will sit raised on the Velcro, running three rows of stitching lengthwise down the Velcro on the leather would be a better long term solution with little to no goo left on the camera should you opt out of that method. I would not be too happy if I had to use a petroleum based product on carbon fiber to remove a failed adhesive...