I think there should be 2, what are really, 2 17mm hex bars (about 2 inches long) that are threaded to bolt the calliper on and the end of the bar is threaded to take a 6mm counter sunk bolt. There should be countersunk washers for the 6mm bolts. Without the threaded bar/bolt the hugger won't sit central over the tyre - at least that's how mine fits. If anyone from here is interested in it I may be able to help out with, what appears to be some of the missing bits
'15 R1200GS TE
'06 R1200S
'04 BCR
Yam SR 500 long term restoration
wanna win the lottery and ride my bike