To be sure, contact the Cody Firearms Museum (CFM) in Cody, Wyoming, USA for a factory letter. You will need to provide them with the exact serial number for this service. Chances are good you will be able to get one as they do have factory records up to serial number #359,999. The letter will be $55 USD or so, but will detail the original factory configuration of your rifle and confirm its authenticity. Typical details included in the factory letter include: date received at the Winchester warehouse (this date is nominally the year of manufacture), date shipped from the Winchester warehouse, caliber, type of barrel (round, octagon or ?), length of barrel, type of trigger, type of butt stock, and special features.
From your picture, it's hard to say if the rifle is completely original as it is difficult to see if the wood is just showing normal wear or if it was at any time refinished. Other parts may or may not be authentic. The top tang should state "Winchester Model 1894", not 94 as it wasn't until 1919-1920 or so that Winchester started to change how it described the gun. Only a good examination and evaluation by an experienced Winchester 1894 collector in person will be able to get you that information unless you're able to take lots of very good, close in digital pictures.
A good source of information is the Winchester Arms Collectors Association website (WACA) which has a forum where you can ask further questions as well as learn about specific reference sources including books regarding the Winchester Model 1894/94 lever action rifle.
If planning to shoot this old rifle, I strongly suggest having it examined by a competent gunsmith who is knowledgeable about Winchester 1894s to ensure that it is safe to do so. Get that finding in writing from the gunsmith. Bore condition should at least allow you to shoot modern 30-30 (30 WCF) ammunition. Part of the pleasure of owning one of these wonderful old Winchesters is being able to shoot them the way the old timers did, back more than 100 years or more ago.
