Hi All, I bought my Primus stove from Sears in the 1970s, it is a two burner propane camping stove ,the same configuration as the current Primus Profile, (but without the igniter). Folding lid and sides yellow, base grey, two control knobs in front. I need to identify the model and number so that I can look for parts. I need to replace both control valves, or rebuild them. Each valve is about two inches long, plastic knob on one end , a pointed cone shaped tip on the other end, a coil spring and a black plastic sleeve. I really most need the black plastic piece. Any info will be greatly appreciated. Mike.