This might have been talked about before so forgive me if I'm bringing up an old subject. I have read in some places the off hand comments that the Shad SH50 top case can be mounted on a Givi SR357 rack mount. Does the Shad mount exactly the same as the Givi E55? I want the Givi SR357 mount for the strength and the Shad SH50 for the ease of use since you don't have to use the key everytime you want to open the box. But obvisiously don't want to have a shakey mount of the top box to the rack. So is it as secure as the Givi to Givi mounting? Thanks for any help.