1903/37 Short Rifle
First thing to check on your short rifle is whether it is a 1903 derivative, or a Gew98 derivative( Both were made up in 1937-1940s.
From the three digit number, I would guess your date in 1937???
The sight ears were copied from the Kar98a, of which many were also "Tuked" by fitting new stocks and bands (the converted 98a's usually have bent bolts, with serrated undersurface of the knob).
These rifles have nothing to do with the later, (and Purpose built) K'Kale short rifles, made 1944-46 only, except for their general arrangement.
As with all things Turkish, what the Turks called them when they made them is unknown...the Importers lump all 7,9mm Turkish Mausers as "Model 38" , which the Turks used as a Generic description, not related to the origin of the rifgles or the variations possible.
Go to Ezboards (Parallax Curio and Relic Board..) for further details in the Turkish board...and my Survey of Turkish models and serial numbers. There is also a link to Turkish rifles which expands on my survey.
regards, Doc AV
AV Ballistics.