Have you looked at this site:
http://community.webshots.com/album/27455338FImWfuvVLR
It has lots of contemporary MKIV promotion materials, some of which you may have, but some may be new to you.
Have you read the MKIV write-up by our own dear Nedsel in the SAAC World Registry? Although it is only 4 or 5 pages or so, it is very fair and informative about the MKIV and it's variants. It also has a serial number list, which although somewhat incomplete, is also the only public source other than the original factory registry. Eventually, all the holes will be plugged, i am sure.
Do you have any specific questions we could answer, kick around, punt or otherwise dodge?