I can't say which neck it is for sure, but the horn is a 156 Aristocrat, from about 1950, based on the serial number. This is the exact same horn as the "Big B" model, except for the engraving. I really don't know what you mean by series III, IV, etc. The pre-war Aristocrat with smaller bell is sometimes referred to as a "series one," but I don't think Buescher ever used those series designations.
At any rate you have a fantastic horn there, for a ridiculously low price (assuming it's in reasonably decent playing condition). It does look like it might be a relacquer, even if some of the lacquer is worn, but at that price it really doesn't matter. Back to the neck, it does not look like the original neck for that horn, now that I look at it.
At any rate you have a fantastic horn there, for a ridiculously low price (assuming it's in reasonably decent playing condition). It does look like it might be a relacquer, even if some of the lacquer is worn, but at that price it really doesn't matter. Back to the neck, it does not look like the original neck for that horn, now that I look at it.