Page 128 of
The Parker Story:
"SELECTIVE AUTOMATIC EJECTORS (SAEs) The idea of SAEs for a double-barreled cartridge gun originated in England, apparently, because Murcotts 1871 patent not only describes a hammerless gun, but his design also features automatic ejectors"
From Gough Thomas's
Shotgun and Cartridges for Game and Clays 1975, page 31:
"The mechanism is in duplicate - one set for each barrel - and is therefore fully selective: it operates only if the gun has been fired; and if one barrel only has been discharged then it ejects only the appropriate case."
Besides, beating a dead horse is one of my hobbies.