Vintage Zippo Pat. 2517191 Salesman Sample? Lighter EX

For sale is a vintage 1966 Zippo lighter. The lighter is in excellent used conditon. This is an advertising lighter but the only thing I can figure out is it may be a salesman sample. The design is a etched and painted 3 color red/white/blue shield with a knights helmet and a question mark. The lighter is a brushed chrome front and back, with polished edges. The cover and hinge are tight, and only very light wear marks. The bottom is marked " BRADFORD, PA. IIII ZIPPO IIII PAT. 2517191. The lighter insert is marked FOR BEST RESULTS USE ZIPPO FLINTS AND FLUID ZIPPO MFG. CO. BRADFORD, PA. MADE IN ZIPPO U.S.A. PAT. 2517191". There is a flint installed and the lighter sparks.