It was the 19AS like you said, of course! The box and papers that came with the watch were also wrong, so the seller apologized and sent a partial refund...
Soon this model of Sea-Dweller will get a cool nick name and be super expensive (this being a bread and butter 16600 from 1993).
This little guy spent it's life on the wrist of a Navy Captain. I purchased it from his niece, and then did a very gentle sympathetic restoration. The crystal cracked at the rim upon removal, so I had to crazy glue it back together and then very carefully polish it. That's why the rust stain was not removed.