VaMLink - by Jeff Oxman.
One
of the cutting-edge areas of Morgan dollar variety specialization is collecting
by sub-variety.

Its not
something that appeals to everyone, but the sub-varieties of the major VAM sets
can be quite challenging.For instance, the 1880-O Overdates presently consist
of VAMs 4, 5, 6, 6A, 6B, 6C 16, 17, 21, 25 and 55. But few collectors, up to
this point , have looked at the die state sub-varieties with an eye toward
putting together a set based on when a variety was struck in the life of the
die.
...few collectors, up to this point, have
looked at the die state sub-varieties...
We're currently doing research
in such die state varieties in order to ultimately list them separately on the
VAMLINK Set Registry. It might also be mentioned that one potential use of such
research is determining the striking sequence of related varieties. As most of
our readers know, VAMs 6, 6A, 6B, 6C and 25 all share the same "Ear Overdate"
obverse die. Therefore, an obverse with no evidence of clashing would
presumably have been struck before a die pair with one clash mark. And so on.