It is great to see these. First, the
Isis variant of this
reverse with the lotus flower is not known for
Caracalla. There are 3 known
reverse dies (R162-164) that replace the lotus flower with a
radiate crown, thus only Nike-Demeter-Tyche-Ma. Dies R162 and R163 have the same
legend as your specimen, MVNICI STOBEN. These are
rare, Josif's single examples are in
poor condition so I cannot confirm whether either is a die match. Secondly, these coins occur with two known
obverse dies, V8 and V52. There are examples in my
Gallery but they are not die matches. You have at least a new die pair. I have not yet found a match for your
obverse die.
I'm attaching a specimen with
obverse V8 for comparison.