Marked only Kettering Special Denver Colorado but looking like late 19th or early 20th century Sheffield or New England manufacture with hand forged blade fitted with rosewood handles set with four pins and one center rivet (I Wilson in Sheffield among others used this configuration). 

Blade had been sharpened in enough to warrant a thinning to bring it back to its original geometry. Fresh sharp edge is ready to get to work. A beautiful old style scimitar here. 

12 blade, 17.5" overall 9.38 oz