I've seen several variationes of these, the two halfs are held together with 5/8" studs ( easy to replace and are the same size as the allignment screw), the holes are over size to be able to dismount without having to separate the clamp completely. The steel piece shaped like a 7 is cut for one size welded at the end of the band and a little shorter where its welded to the side of the band.
Bolt it on tight and with a pipe that has a sag or a lift it will correct it enough at least until you get one or two tacks welded.