I RECENTLY FOUND A HYDRO-TRAC 12 IN A STORAGE BUILDING .. MOWER IS IN GOOD SHAPE .. SPARK PLUG AND STEERING LINKAGE ARE MISSING .. I THINK IT IS A 1969 MODEL .. ONLY NUMDERS I COULD READ WERE 25500 .. WHAT NUMDER SPARK PLUG GOSE IN THE MOWER AND WHERE CAN I FIND THE STEERING LINKAGE ..