This coin is not listed in RIC, it should come after Lyons 102. Lech has a page on this type with this example already listed at the bottom as other specimen.
http://www.notinric.lechstepniewski.info/7lyo-102.htmlI find it interesting that it has been bought and sold so often recently, each time with a price increase.
1. sold on Aureo & Calicó 270 Mail Coin Auction (lot 355) in September 2015 for EUR 320
2. Harlan J. Berk Buy or Bid Sale 196 (lot 264) December 2015 for $500
3. Listed on Vcoins on 4/22/2016 for $625
Constantine I
A.D. 320
CONSTAN-TINVS AVG; bust r., helmeted, cuir., spear across r. shoulder, holding horse by bridle with l. hand.
VIRTVS EXERCIT; trophy; captive std. on ground on either side; A/S across fields.
In ex. PLG