Mongoose is a pretty decent sized company with a lot of products they keep track of. When I did some work for them they were happy to let me put it up in my portfolio, but they were clear that I would need to make it obviously labeled that it was their copyright. I'd be surprised if they objected to your use of their work in the way that you say, but there's certainly no harm in sending them a note to check. if you have trouble tracking down an email address then send me a pm here and I'll track one down from my work with them.

And no worries about the map issue - thanks a lot for passing the question along to the guys who handled it. That was a pretty quick turnaround actually and you did a good job. I'll see what I can do to hold back the stones