P M TR P COS
AVG Laureate head with bare bust of Didius Julianus to the right.
MTR – PCOS Fortuna standing on the left, holding a cornucopia with his left hand and a rudder resting on a globe with his right hand.
Photo of a coin sold the 06/05/2019 by Numismatica ars Classica, Auction 114, lot 745, link to the sale: https://www.acsearch.info/search.html?id=5993580, link to their website: https://www.arsclassicacoins.com/.
All aurei seen with the obverse legend IMP CAES DID IVLIANVS AVG and bare bust share the same obverse die. This die is associated with several different reverse dies for each type. It is therefore associated with the types: CONCORD MILIT, P M TR P COS and RECTOR ORBIS.
The dot between IVLIAN and AVg is very little, other coins confirm its existence more clearly.
For the aurei, the RIC mentions for this type: bust (a) (this one) as well as a laureate bust with drapery over the left shoulder (b) and a laureate and draped bust (c) for this type. I did not find the laureate and draped bust. The source given by the RIC is: British museum (I did not find this coin on their website). The coin probably exists but one can wonder if it is not a mistake. Indeed, the RECTOR ORBIS type is given with a bust (a) and (b) but not for the (c). However, I found for this type the bust (a) and (c) and the source given for the bust (b) is a coin with bust (c). See comments of AYC #5 B, RIC 3 var.