Some time ago I started to collect information about the dimensions of Super-8 film stock. It turned out to be more challenging than anticipated.
My current educated guess about the Super-8 format is documented in the following .pdf-file
I think the dimensions given in the file are pretty close if not identical to the actual dimensions of Super-8 film stock.
Of course, camera manufacturer as well as manufacturer of projection equipment did certainly not always follow these specs - for example, most cameras feature a somewhat larger camera frame than the spec did actually specify.
I hope the document will be useful to someone. If anybody has more or additional information, I am happy to include it in a revised version.