This is a low grade example of what I believe to be an S-143 R5. Because of wear, it is moderate confidence and some will consider it unidentifiable. But I believe their is sufficient detail to identify the type two lettering at R and the imbedded 7 in the bust to identify it as Obverse 21. The Reverse appears to have no stem, but the best distinction is the location of the leaf tip under the middle of M rather than the right upright of M on the S-142. I usually tell people that you should only get it if YOU are comfortable with the identification. http://www.ebay.com/itm/1797-DRAPED...16?pt=Coins_US_Individual&hash=item257a4883b8
I agree with S-143. It is a stemless wreath that means Breen's Rev R or Rev S. The point of the leaf below the center of the M makes it Rev R NC-8 or S-143. On the obv the base of the T is completely over the hair, that makes it S-143. On NC-8 the junction of the hair and forehead is below the center of the base of the T.