First.. I want to say, that's a very nice model

Second.. I think the differences between Max and Gmax will get me into trouble, giving advice

Most important, is that you're learning the true art of modeling for FSX.. in that sometimes you don't even know how or why you figured it out :-?
I will advise though.. that as you learn FSX material options.. you're going to find that it's best to map parts individually, rather than all at once. That will make sense as you get into it.