The gun in question is probably a Special Paragon . The bit of extra engraving at the front of the lockplate is a key. Usually the Special Paragon had a point pattern checkering while the Standard Paragon did not.
P.E.S. marked on the gun would be Paragon, Ejector, Steel [barrels]. Over the years, Baker marked grades on the guns, then discontinued that, and then later marked the grades again. P.K.E /nn would be Paragon, Krupp, Ejector, in model 1909. [a different mechanical design] L.E.S was L Grade, Ejector, Steel [for fluid steel barrels] One will see other combinations of the letter markings depending on Grade, ejectors, triggers, and barrel material.
Engraving on the guns shown above was done by Frank Mason, who really had a good feel for the dog engraving.
If you wish to know more about Baker Guns, Drew Hause saved the old BakerCollectors website to -
http://www.bakercollectors.com/ When looking at the website and selecting something from the Table Of Contents, click on the Table Of Contents item, then click on it again when a new screen appears. Lots of information and photos.