Crane Pre-War in-wall Shower Stem
6 3/4″ overall, 1/2″ diameter. Used in most Tub and Shower applications where the escutcheon screws onto the valve body. Early versions did have the square broach and these stems can be modified to work. May have either ceramic cross, 5 ball metal, or metal cross handles. Same stem fits both hot and cold. Made in the USA.
There are other lengths that look very similar, some are available on a special order basis.