Nice find mate. My all matching 1918 SSA has AD in the same spot. Not sure what it means though.
At some stage someone has given her a light sand so its hard to make out any markings on the timber. All I can read is a Lithgowicon stamp and mk III HV on the butt which I'm guessing got put on there one of the times it got ftr'd in 1943 & 1951.
My one looks like she rolled out of the factory yesterday so I've never been game to disturb the stock and have a look what's underneath.
Hope she's a good shooter for you!