Gentlemen,
I believe you're both right and you're both wrong. I don't have my rule notes handy but I believe the reason the Llama isn't legal is that it is a vented rib. The Colt rib is not. That is not 100% clear in the current published rule book. I will try to reach out to Happy Jack who does not have much internet access while he is at the convention.
As has also been stated, most Llamas also are not true 1911 pistols, with the same function grip safeties.
Basically, to answer the original poster's question, only 1911/1911A1 style pistols and copies are allowed. Llamas are not true copies.