A good fact to keep in mind is that the Rome mint in this period was more than a little quirky in letter forms - particularly R. Some may look like A but more are just R with the legs trimmed off. Since a common mintmark pf the period is R followed by P, S or T workshop letter, the odd R keeps many people from finding the coin.
My photo below (a very favorite coin of mine that just missed my 25 post) shows RT with a well trimmed, almost legless, R. This is perfectly normal. Nore also on the obverse legend that the PF at the right is pretty short legged, too. While we are at it, the A of the period is quite frequently a bit open at the top looking a bit like our H and is very rarely closed and rounded at the top like our cursive capital A. When you have looked at these coins for a few years, such lettering conventions make a lot more sense and a lot less trouble.
