What a great find! Your coin is a variant of
MIB 164c (with
Sear Monogram 25 over the M). As far as I can tell, this is just the second example known of this
type (with the same
monogram on the obv that is present on the rev). The other is in the
British Museum Collection (
BMC 163, RY 24-B, 5.7gm 26mm) that is also listed in DO (DO 111). I've attached a photo of the coin from
BMC Volume I, Plate XXIV. Is there a
provenance on this coin you can share? I try to track these things for very
rare Byzantine bronze coins.
The question you asked about your coin is a
good one - what would be the reason for putting the same
monogram on the obv as the rev above the M?
To make this question even more baffling, I've enclosed photos of 2 other coins (also variants of
MIB 164c around the same timeframe (RY 23-24) that have a different symbol in the same spot that looks like the Greek letter Gamma (
).
Example 1: SB 810,
MIB 164c - RY ? Off B - 4.7gm 23mm
Example 2: SB 810,
MIB 164c - RY 23 or 24(?) Off
- 5.7gm 27mm
On the first example, the symbol touches
Heraclius, but on the second it is roughly equidistant between the figures. It is tempting to think that it is a repeat of the
officina letter on the
reverse, but the
officina for one of the coins is B.
Definitely a mystery!