The
index of
symbols in
Price (
vol. 2, p. 565) do not show any coins with spearheads under the throne. In fact,
Price does not list any tetradrachms with spearheads on them. You mention Kolophon: That
mint did not produce any tetradrachms (
Price,
vol. 1, p. 247 ff); and the drachms minted there
had the spearheads mostly in the right
field.
As for the letter M in the left
field:
Price's
index (
vol. 2, p. 599) shows too many to double-check. But since there are no spearheads listed on any tetradrachms, checking all the coins with M in the left
field would likely turn up nothing.
It is possible that what looks like a spearhead could be another object.
Also, there are many coins of
Alexander the Great that are not listed in
Price.