convertible frame question

I am in the process of refurbishing my convertible frame on a 67. There are a couple of bolts missing (one on each side), that I can not find a description for anywhere. Does anyone know where I could locate a good schematic of the frame with references to the various parts? My shop manual doesn't have one and neither do the various mustang restoration books that I've picked up. The bolts attach an S curved bar to each side of the fram and would appear to be some kind of shoulder bolt or have some type of spacer on them. The PO appears to have repaired the frame before and used a lug nut on the eccentric as a locking nut, and where the bolts are that I am looking for they just threw in a standard bolt that does not even begin to work properly.