The Rigby Serial Number is 5390, on the trigger guard, and below the Mauser action number, 91683. Sold on May 17, 1929 to Marquis del Merito of Spain. He also purchased the following rifles:

5399, 350 Magnum on November 29, 1929, ELDA on magazine box
5401, 350 Magnum on December 17, 1929, Fernan Nuaez on magazine box
5422, 275 HV, on December 17, 1929, "crown over M" on silver oval
5435, 275 HV, on December 17, 1929, "crown over A" on silver oval

Christmas 1929 must have been very nice!