I agree that it is not legal for Pre '75 but it is not a 1975.5 model as mentioned above. Mine was built in 12/74 and it is as much a 1974.5 "type" of model as the Mag Husky, the 1974.5 Maico, the 1974.5 KTM and so on. That is, a 1974 model that had some hurried changes done to it to achieve more travel in the rear. It has a CrMo swingarm in place of the alloy swingarm on the '74 Phantom and a difference in the airbox/rear guard but otherwise the same, even the '75' forks have less than 7" of travel (well mine do anyway). It should belong in Pre '75 with travel limiters in the rear, in my opinion.
Yes, it is an 'AS75' model and hence not strictly legal for Pre '75 but it is prehistoric for Pre '78 competition.
With all that said, Paul's example is very stock indeed and it is a great model and someone should buy the bloody thing, Pre '75 legal or not. Forget about what class it races in - once you've got it in your shed you won't care one way or the other!