Hi Bill,
the main reason to prefer b is that it is always b on related dies.
Actually the coin is struck from die version C2.12 in Füegs great
work on the corpus of nomismata of the time. Interestingly, only one die of this version is known from two specimens (British Museum and an NAC
auction in 1997) and Füeg reads the letter as a b, although it is apparantly a
(or maybe even a tilted
or
?). This probably has escaped Füeg's attention, may be because the available photos were too small.
Furthermore on other dies there is usually a
in the place of
. The
stands for
Despotes. Thus Füeg suggests that the die could be read
but he puts a questionmark on that because the context does not make sense. I think
basileus noster can be reasonable. If
is a tilted
which is used for
in these inscriptions it could even be
augustus noster, but that is also an unusual title. (And
standing for
would make it
despotes noster.)
These inscriptions surely can be tough to interprete.
The coin above seems to be the third specimen from that
reverse die.
byzcoll