ive seen old promo knives that were given away, but they always had the name of the product they were associated with. Coca Cola, Singer sewing machines, and several gun companies for example. thats an interesting little knife....take thos pics to the Bladeforum.... http://www.bladeforums.com/
.....you might get some answers there.
and i wouldnt clean it up, knives are like guns, leave it be!