I looked on acsearch, BMC, Vcoins, Cng, Ma-shops, BM and others the distribution of the different varieties of reverse for the Middle Bronze of Hadrian with DACIA on the reverse (RIC 850; Cohen 531) because those coins are always classified with the same rarity. My goal is not to do something exhaustive, just something indicative. Here the varieties with the head turn on the right: Naked bust + bare head : 5 coins, so around 7% of the total. Naked bust + laured head : 5 coins, so around 7% of the total. Image from BM. Draped bust + bare head : 23 coins, so around 33% of the total. Image from CNG coins. Draped bust + laured head : 32 coins, so around 47% of the total. Image from CNG coins Here with the head turn on the left: Draped bust + bare head : 4 coins, so around 6% of the total. Image from BM. Total : 69 coins. It appears that the coins with the naked right bust represent about 20% of the total, and those with the right draped bust about 80%. This type is quite popular, like all the bronze or copper coins related to Hadrian’s travel, even if the type is not rare but only scarce. But inside this type, there is some big differencies. Here, in my opinion, the rarities levels. Naked bust + bare head : R2 Naked bust + laured head : R2 Draped bust + bare head : C+ Draped bust + laured head : C For the left head, it’s R3.
Well done, also on OCRE (museum examples) the draped bust is much more common. http://numismatics.org/ocre/results?q=hadrian+AND+fulltext:dacia+AND+fulltext:850*
I think that we can find also some differences for others Hadrian's travels coinage, in middle bronze, in silver and for sestertius. And also for gold.
