From a PDF I have of Knibbs book on B.S.A and Lincoln Jeffries
# L15963
Serial Numbers - 15730-16229
Period of Manufacture - May - July 1907
Period of Despatch - May 1907 - Oct. 1908
Notes - Sixth batch BSA Standard & Light pattern. Improved Model 'B'.
Nice piece Kevin. The above is dependent on whether it is single or two screw trigger block?
Do you have any images showing its condition; any information ?