Rare 18th century English wood set

A lovely 18th century part set, matching quite well with my 18th century ivory set (comparison photo of knights included). Kings are 3.65" tall. The rooks in this wooden set have more crenels than the ivory set. Sir Alan Fersht has a similar set on his wonderful website, which he dates to 1750-70. I have seen dates ranging from early 18th century to about 1780, so am unsure on this one.

There is also the tantalising link between this style of knight and early John Calvert sets. The black side is ebonised, rather than ebony, and the set has a wonderful rich patina, as might be expected for such old wood. Marks on bases indicate the turning method used, and the turned pieces have holes in the top where they were attached to the lathe.