It was made by the Wm Rogers Co., it is called Anchor, Rogers, Anchor. cannot find anything about Roman Numeral XII or the Pat. date. Seems to fall 1865 or so.
The patent date of 'May 28/05' likely refers to a design style, type of plating or even the material the spoon is made from.
Stylistically, it dates to the first quarter of the 20thc.
The stamp 'ROGERS XII' would be the design inventory number.
This is Rogers’ (Anchor) ‘Lexington’ pattern designed by Gustav(e) Strohhaker in 1904. The patent date is May 23, 1905 (no.27,438) and assigned to the International Silver Company, so it would have been available to more than one of the Rogers companies within ISC (and others).
The ‘XII’ is not a design inventory number. It’s a reference to Rogers’ process for ‘sectional plating’. On the areas of the bowl and handle most subject to wear, thin sheets of silver were soldered into shallow recesses in the base metal cast. Those were then polished smooth before electroplating the composite item. As per this advertisement: