You can read the pertinent aspect of the license agreement here:
http://www.shelbylicensing.com/press.htm
I've heard rumors that since the suit was filed the full document is currently available 'some where' on the web as it is now considered a public document? Otherwise, yeah, it would fall under a 'need to know basis'.
But what is published at Shelby Licensing is enough to see the primary argument. Shelby wants detailed records of sales, to determine their cut I would think. Products for sale must be pre-approved. Pretty typical and what you would expect to see for such a contract (from Ford or GM or whoever). EITHER side can withdraw at any time by simply telling the other side within a certain time frame within the year.
SAAC's position, relative to the actual license to SELL Shelby 'stuff' is that the license was obtained through 'fraud' some years ago. I DO NOT speak for SAAC, just passing on the opinions/observations I've made along the way. I don't see anything in the agreement that gives Shelby the right to the registry and certainly no right to acquire/use the SAAC name. Nor does the license agreement address the return of Shelbys personal 'stuff' (what ever that is supposed to be).
An interesting question might be: ASSUMING the license is in fact valid (a legal point of dispute) what should/will happen to the various trademarked 'goods' in SAAC's possession (hats, badges, etc.)? I would guess Shelby considers the registry to be part of the SAAC 'stuff' for sale and that is the basis for his legal argument.