I just got this one in a small group of coins and it is a little rough around the edges but it is unlisted in RIC with the combination of obverse legend (1g) and bust type (BB). It should come after RIC VI London 141. It is in Huvelin (#12) and Lech has
several examples on his Not in RIC page; so even though it is not in RIC, it is actually not that rare.
Constantine I
Circa A.D. 311- 312
19x21mm 2.8gm
CONSTANTINVS AVG; bust left, laureate helmet, cuirassed, spear over right shoulder, shield on left arm.
ADVENTVS AVG [The arrival of our Emperor] Prince riding left, r. raised, l. holding up spear, on horse pawing seated captive to left, star in right field.
in ex PLN
RIC VI London --