It looks like it may be a KAAZ, but they mostly make stuff for riceburners..stand bye

maybe?...a Drexler? (scroll down) http://www.drexler-motorsport.com.au/products.html

Whatever the case, I have several Ford units lying around, back in the day (late 60s early 70s) it was rumored that the Nelson bros that ran a very competitive Gasser Camaro used a welded rearend. From that time on welded diffs have been called "Largo lockers".

Anyway. I'm assuming that the broken bolt holds the pin that goes through the center of the carrier (probably under the snap rings) you may end up beating the living hell out of this thing to get it apart. In any case remove those snap rings and see what's there, you can rotate the assembly? right?