I just looked it up in my Renneberg book (1st Ed.) on the Model 94. The factory drilling of side mount peep sight holes began around serial number 1,940,000 (early 1953). The carbine in the picture above was made in 1953 (serial number 1,951,XXX) and is an early example of the M94 with the factory drilled holes. The receiver holes were drilled in the receiver by the factory until the Angle Eject feature was added in the Post-64 era (1983, around serial number 5,200,000).
