That's a really interesting coin! It looks to me as if there's a bottom serif sticking out the bottom loop of the B-shape. If you look at the E in George, that also exhibits B-like qualities, but looks more E-like?The whole die and/or punches look very tired. So, is it an E with a damaged/curved bottom bar, or a B punch refashioned (for God knows what reason) to make an emergency E? Or B/E? Food for thought! The serifs of the E in Georgius do indeed display unusual wee spreads and bends but the corresponding letter in Rex has strong 'B' loops. Exactly the same as the St. James coin.