WES stands for W.E. Strong & his cartouche may be found on Colt M1911 Pistols & M1903 Rifles 1909-1918.
The S/N dates to 1907 which makes it a Low Number (below 800000) Single Heat Treatment receiver. See ViShooters excellent website, http://vishooter.home.att.net/m1903.html
The bolt appears to have a staight handle which most probably makes it a SHT bolt. What markings are on the bolt handle or safety lug? John Beardhas an excellent chart on ViShooter's website that allows you to date your bolt. Few straight handle bolts have the improved, Double Heat Treatment. The best known DHT bolt with a straight handle is marked "J 5" on the safety lug. But, the "J 5" bolt bears the distinction of bridging the transition from straight to swept handle.
Since the receiver & bolt have the SHT, most people consider them unsafe or at least have an increased risk of shattering when fired. This has been discussed on CSPat length several times. To sum up the discussion, some LN receivers were heated too hot during manufacture to the point the steel was burned and the grain structure affected. The burned steel is brittle. No definitive way is known to identify what receivers were burned and which were not and thus determine how strong any particular receiver is and which are likely to fail. The problem is the marginal strength of burned steel. Its strength is reduced but is adequate for a round of ball ammunition. But, if a cartridge has a pierced primer or splits on firing, the force of the gas escaping into the action exceeds the strength of the steel and causes the receiver to shatter or blow up. These receivers are known as Single Heat Treatment (SHT) receivers; later ones were double heat treated (DHT) or nickle steel (NS) and are much stronger.