A) Your air rifle was despatched from the BSA factory in Birmingham on 12 July, 1912. The number 2 stamped beneath the third digit of the serial number indicates that it was produced in .22 (No 2) calibre. The rifle, as you state, is an Improved Model D and is also a full-length (45in) Standard Sporting Mark 11 model as it has a loading lever operated by a side button on its left-hand side. This was incorporated so that a sling eye could be fitted to the lever itself and the rifle used with a leather or Canvas sling. This fastening was a Lincoln Jeffries patent No 25,783, which was accepted in 1910.
Your rifle is fitted with a full length (14in) stock made from Italian or French walnut. It was the top of the range air rifle of its period, selling for 45 shillings (£2.25).