is it legal for me to purchase a united states harrier jet? if not, according to what statute?

Will require specific licensing just like any other firearm. SELLING to you, however, is totally illegal.

Seems to me I have read over the years of a privately owned Harrier Jump jet. They are pretty old at this point- I remember building models as a kid ~ 35 years ago.

I would think before they entered the private market any armaments or classified aeronautics would be removed.

I suggest googling "private harrier jet" and seeing what comes up...

Since it's just a plane, and they obviously would not sell you a fully armed or capable model....I don't see the issue.

Other then the fact that they cost millions of dollars each.

Wouldn't you rather just buy one of those new one-person jets on the market....much cheaper.

If ya gotta buy a Harrier....get it from France. Much cheaper.