Marty I added better pictures on the Rear End/Differential thread at this link: http://6364cadillac.ning.com/profiles/blogs/differentials
Note, That I have pictures of 3 1964's with the Controlled and they are in the same location as posted in the link and on my car. I did find a 63 with limited slip and it was in the same relative location, but on the left side, so perhaps 63's was on the LH side. I know even on the 64's they are in the same relative spot but have seen them up or down an inch or two. Either way no one would knock any points off at GN judging regardless or side. I will dig around my parts car pictures some more.
Thanks Jason , I wasn't that concerned abut the judging points I was more concerned of you seeing it in the wrong place and asking why I didn't ask you where it went : ).