http://www.mcestoril.pt/le-mans/index_gb.html
If you look at the entry lists from the 70's on this site there is a list of cars not accepted into the 24 hrs then. If accurate it makes interesting reading, Franz Konrad didn'nt have much luck then either! his 935 was turned down in 78.
It seems that there are more theads on who DID NOT get in the race than those who did. I think its time to move on, as unless the ACO release a list, it is pure speculation on how even tried to enter.