Information from worldbayonets.com:
This example was made by Victorinox AG in the 1934–1949 period. Victorinox was located in Schwyz Canton. This example was made prior to 1950, when “Victoria” was added to the ricasso marking.
The bayonet and scabbard are unissued. The bayonet lacks a serial number and the scabbard’s frog securing tab lacks a buckle hole. The serial number was applied only when the bayonet was paired with a rifle. The scabbard’s buckle hole was punched when the scabbard was first mated to a belt frog to ensure a tight fit.
Based on serial number data, it appears that Victorinox initially produced the M1918 bayonet until the early 1920s. Elsener resumed production concurrent with introduction of the M1931 Short Rifle in 1934 and continued until M1931 Short Rifle production ceased in 1958.
The Script-P mark identifies the scabbard maker as the firm Paillard AG of St. Croix. Paillard was a very diverse manufacturer who produced an amazing variety of products over its 160 year history. The firm began in 1814 as a watch-maker, however, also produced music boxes, record players, typewriters, radios, and the famous Bolex line of motion picture cameras.