My Tower & Lyon catalog came today. It is a reprint from ca 1904 and It clears up, to me anyway, why you don't see many of them...they were expensive.
The one I posted was marketed "for Jewelry Manufacturers, Amateurs and Light Work". It was available with the flat base, as shown, with and w/o the anvil, and nickel plated. The base vise cost $3.75. Add $.75 for the anvil, and a whopping $2.00 for the plating. By contrast a swivel base only added $.75.
The standard vise was available in 6 sizes, ranging from 2 in. to 6 1/2 in. The 6 1/2 in. One opened to 11 in. And weighed 160 lbs. Cost was $33.00. A rather large sum back then.
The sizes were 2, 2 3/4, 3 1/2, 4 1/2, 5 1/2, and 6 1/2. They were available in both fixed and swivel bases.
Mike