This coin just sold for 421.00 euros or $523.00. It is not in RIC for this bust type. Lech has examples on his page-
http://www.forumancientcoins.com/notinric/6lon-261_r.htmlConstantine I
A.D. 312- 313
22mm 4.0gm
CONSTANT- INVS AVG; laureate bust, wearing mantle and holding eagle tipped scepter, facing left.
MARTI CONSERVATORI; Mars in military dress, stg. r., reversed spear in r. hand, l. on shield set on the ground, cloak across r. shoulder, star in left field.
in ex. PLN
RIC VI London –