How old is the publication?
(just looked it up, 2010)
The challenge with fowlers is that unless they are of a specific type (Hudson Valley, club butt, New England) they are hard to date by style. Then folks rely on the furniture, barrel, lock, and so on. As stated, a restock of old parts is possible. And fowlers could often be imported for less than they could be made of new parts in that era. But, I’m not a published expert in this area, so there’s that.