These nest two specimens came to me via two separate auctions on E-bay. The first was purchased as "Phacops granulosus". The second came from Sahara Imports and was labelled "Gerastos". It's taken me a little digging but I've found more instances of Proetus (Gerastos) granulosus (from the AM Limestone, Mt. Issoumour near Alnif, Morocco) than Phacops that match the trilobites that I have.
As this is a Proteid trilobite it should have holochroal eyes, but I've not seen any specimens that ever show the many lenses that should be evident. It's a cheap (good specimens can be had for under $25) fairly common species so I can't believe anyone would waste their time trying to fake them.