Moxhams Antiques has dated this piece to the Georgian era.
I read in Susan E.Stewart Gillows Book that painted cornices became fashionable after 1780 for pratical reasons ~ carved cornices collected dust and were difficult to clean at height. The author also says that though Gillows would often supply the complete bed they often just supplied the carved mahogany posts and left the fitting of the oak rails and deal cornice to the local joiner.

Provenance Yester House, East Lothian, Scotland a fine Palladian House which was worked on by the architects William Adam and later his sons Robert and James for the Marquess of Tweedale. Photos show the bed in situ at Yester House.
Circa 1780
Moxhams Antiques has dated this piece to the Georgian era.
Roger and jill founded the business in 1967 and their son nick joined them in 1994.
You can view the stock and full dealer information on the Moxhams Antiques Profile Page
Moxhams Antiques is a registered member of BADA