I have come across another mention of the GEERING family of Hailsham, Sussex in a book about Captain Barclay, entitled The Celebrated Captain Barclay – Sport, Money and Fame in Regency Britain by Peter Radford (Headline Book Publishing, 2001).
This biography of the ‘celebrated pedestrian’ contains one paragraph about “Mrs Gearing’s Drug Shop”. Unfortunately it is mainly based on the work of Thomas Geering, which I am of course already aware of. There are however a couple of fresh clues in that one paragraph, which add to the GEERING story.
The paragraph begins, “Robert was always fussy about his accommodation. On Monday 1 October  he packed his deal trunk and moved into new lodgings suggested to him by his barrack-sergeant, James Gearing – the small front room of his mother’s drug shop at Hailsham.”
So it appears that Captain Barclay moved to Hailsham on the 1st October 1804. I can’t see where this date comes from, but perhaps I can work it out (or ask the author).
Furthermore it appears that Captain Barclay had previously been barracked in Eastbourne, Sussex, so presumably this is where James Gearing (or James GEERING my 5x great-grandfather) had been barrack-sergeant and not at Hailsham barracks.
Useful clues, and hopefully I can use this date (1st October 1804) and location (Eastbourne barracks) to pin down some details for James GEERING in the form of a service record.