Posted 02/22/2008 7:52 pm
Neff, San Fransico made both circulating and proofs in 1981. Most filled mintmarks look rectangular and filled in both loops. I don't know if it's the angle of your picture or is the 3rd star up smaller with one long point and the rest shorter? Breen does list a varity for that and I believe it is on the proof coin. If it's a proof, you should be able to tell by placing it next regular coin. Surface area will be much smoother and shinyer. Photo isn't clear enough for me to really form a good opinion.
