You have to license the buyers and make them account for every lb they recycle by having the serial numbers to compare it. They would have to submit those number as soon as the buy one. If the converter doesn't have one they can't buy it, and setting up stings for that would be pretty easy.
Well, it starts locally. A meth head stealing a converter isn't going very far to sell it. Odds are most are sold to junkyards that sell them to a larger recycler that processes the PGMs.
I think it's a bit of a stretch to assume that entire illegal market could move offshore without a trace.
