I have never seen this coin before.
CONSTANTINVS PF AVG
MARTI CONSERVATORI, Mars standing left, Victoria on globe, shield and spear in right hand. TT in exergue.
RIC VI TICINUM 121
Nice...I don't recall seeing an example before
I remember one from the first workshop already posted by Nikko on nummus-bible.
http://www.nummus-bibleii.com/t6365-tres-rare-marti-conservatori
When I first saw this new example for sale, I believed that the strange reverse was due to double struck....but in deed not. :D