Sorry I can't help, but I am posting here to see notifications of this thread.
Since I had 3 of those, I researched a lot online, I do not have the metcalf catalog but everything I found is a lot bland, inconclusive, shallow. . All Bohemund have same legend, and there are infinite types, how would any researcher know which one is which.
I guess there are so many variations that in reallity, no one really knows anything.
I don't have a copy of Metcalf either, though I see it's available at a university library not too far from me.
I will make a wild guess that maybe the letterforms are used to some extent in determining the classes. Yours has the A with the top bar tippped with pellets, and on other letters (and the crosson the helmet) the long diagonal serifs that look like tails, so maybe look for a subtype with those chracteristics?
Same letterforms for the A, and for the distinctive “elongated” S in BOAMVNDVS.
Bohemond III took the throne around 1160 when he was only 12 years old ("minority" before we was of age to rule on his own). I think 1163 was when he came into his “majority.” (Wikipedia).
Please add to the catalog! I would just title it Denier - Bohemond IV or Bohemond V, Class O (we don;t need tete casquee since they are all this style anyhow).
We could clean up this section and get consistent nomenclature.