Okay, sorry for quadruple posting, but I'm undoing the barbacks and I need to know about mounting the clamps back up to normal standards.
shows part #2 as having a stud in it. Whoever installed the barbacks removed it and put short bolts from the underside. I could use a stud I suppose or run a bolt through from below as they did (theirs are too long and have chipped threads), where #9 and #10 are. Which would be better, and what size bolt/stud would I need?
Ended up being a 1.25 thread pitch, M8. I used bolts from the underside, about 40mm long. Was a pain to get in and I'll probably replace with studs to make it a little easier to line everything up.