Or, modify that one. My thought - drill for a #2 or #4 screw though the outside plate, run a nice neat SS pan head from the outside, through the outer plate, through a bushing made from aluminum or steel tubing, though a washer, through the cutout on the inner cage plate, through another washer and a lock washer and nut or just a red locktite'd nut. Cut off the bottom of the cage. Could look like it was made that way.

Ben, the guy who enjoys making bikes different. (I have three I could show you for inspiration.)