Best mount I've used has been attaching a magnet to the tripod mount.
Pick one of these up at harbor freight and steal the magnet off of it. All tripod mounds are 1/4"-20 threads, so you just run a bolt through the middle of the magnet. The tripod mount is also handy since you can fab up just about any mount and attach it with a bolt.
I was having a couple things done, had my laser guy add these i designed to the mix to try out, will probably weld a few here and there on the chassis so i don't have to worry about tape and it cost next to nothing.