I posted some time back about this mould I bought at auction, but never did followup with pics. In my search for an unvented 358156 mould I ran across this. The pics shown are from the original auction except for the last one showing the imprint on the inside of the box lid. I don't believe the seller even saw the imprint, or perhaps he didn't realize its significance.

My apologies for the pic sizes, this was my first attempt at posting pics here IIRC.