none taken...The link is for you to look at the various types of 550's, find yours, and look up Honda part numbers for items you need.
Your caliper, however, does not look like its from your 78 550K.
The FA12 pads come with the 'nub' in the package.
Its actually a screw that fits into the top of the pad to keep it from rotating in the caliper.
what is overseas?
Duanob, dave500, and TwoTired are the members you want to chime in...