I have a Whelen Lean to from Duluth Tent And Awning, that has the smell you describe. They claimed it was the waterproofing/fireproofing that they use.
I've had it for quite a few years, and it still smells, even though I use it on a regular basis, and have left it out to air several times.
The saving grace in my case, is that It's a lean to, open in the front, so It's not too overpowering. I got used to it, but something enclosed, with as strong a smell as you say yours has, would probably be a different story.
I'm sorry to say that I can't really offer any advice other than what's already been suggested. Good luck with it, and on your hunt.
Bob