Gold Keeper Ring

by George
(Lincolnshire)

I have inherited a gold keeper ring with the following gold markings on it:

KBSP: Sponsor or maker? Do you know who or when?
Crown symbol and 18: I assume 18 carat gold.
Anchor symbol: Birmingham assay office?
Letter "d": Year, could be 1801 or 1903?

Which year would tie in with the maker?

Thankyou.