Check this link:
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA065940&Location=U2&doc=GetTRDoc.pdf
It is a pdf file (downloadable) of an Army Air Force/Elgin Field Test Ground report titled "Comparative Test of the Effectiveness of Large Bombs against Reinforced Concrete Structures (Anglo-American Bomb Tests-Project RUBY)" produced in 1946. It has test results for various Disney bomb configurations and on page 88 is a partial cutaway drawing of a Disney bomb. Be advised that the pdf may take a while to load: the report is 319 pages long. If you have any problems downloading, send me a message and I'll e-mail you a copy of the file that I downloaded.
It is possibly a flaw in my character, but I often can't resist trying to find the "unfindable", so I took your request as a bit of a challenge. You are right; there is very little graphical material regarding this device. If I should come across anything further, I'll post it here. I hope this is of help to you.