<-- From an ex-aspiring model. Now an aspiring designer.
To put it clearly:
If you are under the height requirements there is little if any chance you will become a successful fashion model. When modeling you have to fit into the clothes properly; its all about the clothes, not you. If the outfit looks awkward because you are too big or too small, they will not bother tailoring. It's easier to get another muse who does fit the bill.
Just remember, there are tons of guys that fit the strict requirements, what do you offer that the rest don't?
I'm not trying to break anyones dreams or aspirations. I wish I could be a model, but unfortunately I know I don't fit the rquirements, and calcium pills won't help either.
.. I hope I didn't sound too harsh!