Hello all.
I was recently given a 4 reales cob, apparently from a shipwreck. I suspect it has been clipped, as it weighs in at 12,13 grams and normal 4 reales cobs are north of 13 grams. My knowledge about these types of coins is very limited so I was wondering if someone here could give me some feedback on mint, assayer and approximate year.
Pictures below

