This Falling horseman from Alexandria is quite uninteresting apart from the apparent difficulty that this engraver with forming the Rs on the reverse legend. They look very much like retrograde Ns. His formation of Ps isn't much better, looking more like a bowed capital D than anything else. Anyway. I thought it worth sharing to see if anyone has any thoughts. Constantius II - AE2 Obv:- D N CONSTANTIVS P F AVG, pearl diademed, draped and cuirassed bust right Rev:- FEL TEMP RE-PARATIO (but Rs seem to be made from Retrograde Ns), Helmeted soldier left, shield on left arm, spearing falling horseman; shield at ground to right. Horseman turns to face the soldier, and reaches his left arm up towards him. He wears a is bare headed and a bearded Minted in Alexandria (G | // ALEA). 15th March A.D. 351 - 6th November A.D. 355 References:- RIC VIII Alexandria 72
That lettering is pretty distinctive! I think it’s as you said and he was just having some “difficulty” with those particular letters, for whatever reason. With a bit more effort (on the part of the die engraver), I can see those Ps and Rs looking typical.
I find it amazing that as many of the letters were as similar from mint to mint and century to century as they are. We just have to learn what we can of the odd ones and where they occur.