A new stem assembly ordered from OldColemanParts just arrived meaning this Speedmaster is back working safely again. I've included a picture of the faulty stem that had been cut downhand the thread split, for reasons I can't fathom. The result was the stove couldn't be shut off. I bought a NOS generator as well as the stem assembly. A very nice touch of Bob at OldColemanParts to include a badge with my order.