I just stumbled on a similar seal in
Jordanov, I. Corpus of
Byzantine Seals from
Bulgaria. (
Sofia, 2003), p. 70, 67, dated 13th - 14th century, found in Sophia. The figure is described as St. Michael,
nimbate and winged, standing facing, wearing
cuirass, short
chiton and
military chlamys, sword in right hand on shoulder, sheath in left hand (sword and sheath reversed on yours). The
reverse is, like yours, the official's name and titles. I am sure it is not the same as yours. But I think the
obverse description and like the date will be a useful start for you. Unless you can read the
reverse, you might not be able to get much farther.