Not likely a sting as the information is too ponderous and vague. Generally speaking, in order to make a case in court for the defendant having "clear intent" to break the law, the law enforcement entity cannot be seen as having generated the plan and then provided the means. Of course the arrest of those six hapless dipshits in Florida might suggest otherwise. If that was not entrapment then the definition of what is has certainly shifted.
As a side note, I had a Saudi Arabian who claimed to represent some firm there contact me about making 100 flatbed linkers in 5.56 caliber. I declined and he started giving me the full court press. I kept my refusals clear but he kept pressing, so I finally contacted the FBI. I don't know if it was an attempt at a sting, but the idea that it might have been was a little creepy. The whole concept smacks of, "We can't catch the ones already breaking the law, so what say we create some criminals of own and bust them!?"
Best to steer clear of anything that even hints at impropriety when dealing with federally controlled weapons and parts. This guys just sounds like an "English as a second language" fellow with a shallow understanding of the law and no radar whatsoever.