I recently won the first coin below on eBay and it's not listed in RIC for the right facing buckler/spear bust. I have had two other examples, though I sold one. The other coin that I have (second one below) is an obverse die match; but interestingly, the reverses are different dies.
Constantine I
A.D. 318-19
19mm 2.7g
IMP CONSTANTINVS P F AVG; laureate helmet and cuirassed bust right with spear across right shoulder and shield/ buckler on left.
VICTORIAE LAETAE PRINC PERP; two Victories stg., facing one another, together holding shield inscribed VOT PR on altar.
in ex. ΓSIS
RIC VII Siscia --