Rare Vtg Antique Montgomery Spark. Plug Mfg’d Franklin Ohio Hit Miss Gas Engine. Here is a nice old “M” (Montgomery) spark plug. I have included many photos to show its condition. This rare old plug will make a fine addition to your collection. The thread size is 1/2 inch pipe. Please call if you need additional information. Package will be insured upon request. Most items are packaged with new bubble wrap and new packing peanuts. Sometimes prices are inflated due to the weight of the item. I require all international packages to be insured. Be sure to check out my other auctions and store PLUDGEWORKS. _gsrx_vers_526 GS 6.6.6 (526). Sellers: Get your own map today. The item “Rare Vtg Antique Montgomery Spark Plug Mfg’d Franklin Ohio Hit Miss Gas Engine” is in sale since Friday, November 13, 2015. This item is in the category “Collectibles\Transportation\Automobilia\Spark Plugs”. The seller is “pludge” and is located in Carleton, Michigan. This item can be shipped to United States.