That was my first impression, but the more I looked at it... The R in the coin on the left has brackets (little wiggles) that come out of it, which aren't present in the one on the right. I have also seen a number of R's that are open at top, but the stems (two vertical bars) on the letters are quite similar and have the same structure of other A's in the same
legend. The right stem of the A in question is quite straight, and both brackets are the same length (an open R would probably have a slightly shorter right stem). As a point of comparison, the "P" at the beginning of the
legend does have a bracket, which should be present in the R.
Or maybe I'm just seeing things!