There are a lot of factors that go into 1903 values. Of all the American Milsurps, the 1903 probably has the most variations and small details that affect the value, as compared to the M1 Garand that really only has the date of manufacture, the manufacturer, condition, and parts matching to consider. The 1903 is a good bit older, so there are a few more variations, rebuilds, etc to work through.
There are a lot of markings on different parts of the receiver and barrel that will help identify the rifle. But based on the photos you have given, it is what is considered a "low number" 1903, and your 299XXX serial number puts it as a 1907 manufacture date. Anything made by Springfield with a number less than 800000 is considered a "low number" 1903, and they are widely regarded as unsafe to shoot. At that time, they were only heat treating the receivers once, and they were found to sometimes rupture when fired, so they started double heat treating them after serial number 800000.
Many of these rifles still saw service and were used in both wars, some being rebuilt like yours was. The O.G.E.K. in the rectangle cartouche on the stock means it was rebuilt at the Ogden Utah Ordinance Depot by Elmer Kieth (or he was the officer in charge). This likely means the barrel is not original to the receiver, but that your rifle was probably used in WW2.
There are a lot of other small markings and details that you can find on it that will help narrow down its value. But on the face of it, the fact that it is a "low number" 1903 means that you'll need to find a buyer (if you are actually wanting to sell it) that wants it as a collectible, not a shooter. It may be safe to shoot 1000 more times before the receiver decides it wants to come apart, or it could be the next time the trigger is pulled, you have no way of knowing.
But to give you an estimate, based on a quick Google search and the info you've provided in the pictures, some similar rifles have sold in the $900-$1200 range from what I've seen.
