The small co2 bottles are "Soda Bulbs". After looking at it more closely I see a nice newer looking plastic formed co2 holder. Even the engine case appears to be plastic. I want to get some pics up, if someone has a cell phone I can send the pic there and get it posted. Its probably not anything special after further looking, but Id like to know more about it. A gentleman from my town brought it over to me. He said it was told him it was an antique. He knew I flew a lot of RC disciplines so he just brought it over and gave it to me.