Thank you very much for the comprehensive information, it certainly helped me build a better understanding of Watson Brothers.

Some further information, the serial number of this particular Watson is 8665. It is a sidelock with no underlumps, and a concealed third bite. It is completely engraved with "Watson Brothers" across each of the sidelock. The case colors are around 90%, it is an ejector with 30" barrels. The timber is magnificent, with the tear drops at the end of the comb.

Again thanks to everyone, I really appreciate your help.