what specifically do you want to know? You pretty well have it...
the H above the lever boss is meaningless in this case... just an inspector stamp.
the tang sight was not a standard item, standard would have been a rear sight called a 15WG. Your tang sight is either an Lyman 1A or if it is windage adjustable then a Lyman 29 1/2.
You are right in that this gun is a first edition of the 250-3000 and was the eventual precursor to the 99G.
The trigger should be checkered and the bluing should have a deep luster. It was the real first mass produced model to come with standard checkering... some might want to argue that the 1899CD was but I really don't consider that a standard full production offering rather more of a by order only gun.
They are a desirable model of the 1899/99 if they are in good shape.
