This coin is not in RIC; but it should come after London 76. Several examples are already known, and it is in the London mint book by Cloke & Toone.
Constantine I
A.D. 316
CONSTANTINVS P AG; laureate and trabeate bust left.
SOLI INVIC-TO COMITI; Sol stg. l., chlamys across l. shoulder, raising r. hand, globe in l.; S-P across fields.
In ex. MSL
RIC VII London—; Cloke & Toone 8.07.020