Very old English set, late 18th century?

A wonderful old English set, made from boxwood and rosewood, with what I would call "solid" turning - not overly refined, and with quite a dose of variation between the turning; perhaps a good sign for an old set. Kings are 3.44" tall.

The knights are well carved out of one piece of wood ("monobloc" knights), in what appears to be a similar yet more evolved form of the basic washington or philidor style knights from the latter half of the 18th century.  Other features which might indicate an older set include the similarity between the kings and queens, as well as the distinctive turning marks both top and bottom of the pawns.  Many of my older sets have holes in the top and bottom, but this set has obviously been held slightly differently in the lathe - possibly indicating this set is not quite so old, however (though please do contact me if any of this dating evidence points in a different direction!).