You know my answer already.
However, all GM crafted coal items will have a totel of 21 resists. It's been forever. I'd steer clear of unmarked platemail, chainmail, ringmail. Chain & ring is so easily crafted it rarely went unmarked, or unexceptional. We all know why.
Here are some examples of Coal and NPC Armor (Evista[Trammel Skara West] and Phishman's Vendor Museums[Just outside of Cove, Felucca])
http://i20.***********/24o58gw.jpg
http://i21.***********/2v0zijc.jpg