i am using kadee #5 but i bought a kadee gauge and the had a #58 in it and i like the look but i have $60 in couplers siting on my bench all painted and waitng to go in to the cars. what is the real difference between the two. also what is the best way to mount them to the body. i buy the bulk packs of couplers and the dont have the gear boxes is this what i have to use to mount them to the body.