Relative dimensions of the pegs, press-stud, and hook plate. However Kelvin Dodd of Moss America has written to say: "In reality, the rear snaps moved around quite a lot when the V8/rubber bumper shell was built. Iíve done some research on this and have found that the stud location on the cars up to 1974.5 is pretty standard. From then on the snaps vary even from side to side. To allow the later tops to fit these later cars accurately the snaps and even the cut of the top from some manufacturers is slightly different."
The positioning of the press-stud is dependant on what tonneau or hood cover you are using. I've had two full tonneau covers and both fitted my stud in this position, but I have seen others with a smaller spacing i.e. a bigger gap to the front socket.
The pegs are secured with washers and nuts that are a fiddle to get to, this picture is of the off-side. The rear one (A) is accessed through the arrowed hole which is awkward enough, but also to one side which is why you can only feel it and can't see it without a mirror. The next one moving forwards (B) is easier to access, and the other two further forward still are accessed by removing the trim panel aft of the doors. 'C' is the carpeted wheel arch, 'D' the cockpit rail, 'E' the straps that go round the folded hood, and 'F' the rear bulkhead trim panel. 'G' is a gash bolt I have screwed up from below to block off the hole that was used for the static belt quick-release fitting, to prevent water running down.
An 8mm or 5/16" socket is a snug fit on the nuts, or a 2BA spanner. However whilst I can get my miniature 1/4" drive ratchet and socket on 'B' above there isn't enough room for 'A'. But a 6mm Allen key (or 1/4" square-section bar of your choice ...) can be wiggled into the 1/4" square drive of the socket, and that will just fit on that nut. Also note that you don't really need to turn the nut, just hold it in position, while you carefully screw the peg down into it. Stuff the socket so the washer and nut sit just below the top otherwise the stud won't pick them up. Do that before putting the stud in the hole which will allow you to align them with the hole as well as give you more space. Use a soft washer of some kind between stud and body to protect the paint, I used offcuts of vinyl used to recover the cockpit rail or dash.
The two 'teardrops' for the rear of the hood and tonneau cover are accessed from the boot, via a hole near the lid hinge.
Rear retaining bar, little vinyl boots glued on the ends, a shade under 35.5" long
The main bar curved as well as chamfers on one side of each end.