This bagpipe was likely made in the early years of the 20th century. John Grey & Sons was a trade name, and there's a good chance the pipes were made at the Starck shop, or at another London bagpipe maker.
The set is complete, comes with a War-Mac chanter, and currently has a very old Canmore bag on it that I'm happy to ship, but would recommend removing and replacing. The blowpipe looks as though it has a crack near the bottom, but these have not been played for some time, so it's unclear what the effect would be.
The scrolling maker's stamp appears on all the pieces except the stocks. The chanter stock has no ferrule, and may be a replacement.