All combat should be approached with evolution in mind, especially within the combat itself.
Well said :) KendalGuro. That is true of tradition.
Sorry for the thread necromancy, but I just came across this one today.
There have been a number of good responses to your question. My thoughts are that it is pretty unlikely that any FMA systems are being taught and trained the exact same way they were 100 years ago, even if they were in existence at the time, which is unlikely in most cases. The reason for that is pretty simple, most of the systems were kept within a particular family, and there was no effort at all in cataloging them for teaching in the first place, and definitely not for retention of purity or for passing them on to future generations.
Having said that, I think it is easy to say that many of the systems that are in place today will be kept for 100 years or more. This is much easier now that there are actual curriculum which have been developed, and documented video of the techniques, to go along with the direct transfer of knowledge from teacher to student.
FMA are hard to find most places in the USA. It can even be hard to find in most places in the Philippines. Cebu seems to be the hotbed for FMA.