Six Key Mine is number 9 in Robert Rose's Mental Block Puzzles series. This specimen is an original Rose, exceptionally rare to find. One of the six keys is labelled "MBP 9 6 Key Mine". This puzzle has never been solved, new in condition. Buyer to pay shipping, calculated after auction.This puzzle comes from the collection of the late Saul Bobroff, which we are selling on behalf of his widow, Paulette.
$300.00