Think I answered my question. The parts are the same, but one of the part numbers is an older version. Who knows why they needed to re-number the same part.....
Maybe from a different vendor made to Honda specs.
From looking at the fiche... Nissin is the company that made the caliper for 97 Valkyries and "unspecified" is the
company that made the rest

... I guess they're all functionally equivalent... I'm sure my 97 Valkyrie doesn't have
a 97 rear caliper on it, at least not on purpose, I changed out the one that was on it when I got it with a used one
from eBay...
-Mike