Honestly, (I am a teeny bit of an expert on purebreeds, just a teeny bit though) I would hazard a guess that your little guy (what's his name?, and more pictures, we always want more pictures) is of the modern "type." As to his health I would: a)take the horror stories you have read with a grain of salt (a big one). I have encountered quite a few Siamese (etc...) cats at shows, I have never seen one with the sunken eyes the horror stories mention. For delicateness, every one I have held felt more like a small, fuzzy, and purring brick, not at all delicate. I think that very short, less dense hair on the Modern Siamese simply fails to hide a slender well built cat. For example take a normal domestic and dunk it (well, don't actually, neither the cat nor you will be very happy about it, just observe a bathing instead) and you can see just how little (or so it seems) cat there is under all of that fur. None of the extensive veterinary literature I have perused mentions anything special about Modern Siamese having significant health problems (other than the usual raft of genetic disease each breed seems to have in very small numbers). And, b) consider the source of the "tales of woe." Why?
Many Traditional Siamese breeders and Modern Siamese breeders don't seem to like each other (hate is a word often bandied about, unfortunately) and obviously they disagree about how their favorite cat should look. Each variety of breeder seems very opinionated about the other's cats and I have heard a number of nasty things said by some people. The Traditional Siamese breeders (as a whole, not necessarily every individual) seem to think that the Modern Siamese breeders are breeding nothing more than misshapen, hideous monsters that have no place in polite society. While the Modern Breeders (again, not everyone) talk like the Traditional Breeders are breeding nothing more than alleycats which just so happen to have seal points. So honestly, I wouldn't listen to anything one camp has to say about the other.
Anyway, he is a real cutie.
Note: for an example of an even worse "catfight" about breed definitions do a bit of research into the Ragdoll. Whew, that is quite the row.