The box shown below, model number 931 sold by Proto Tools, is clearly a very late model Millers Falls 1124, to which it appears to be part-for-part identical. The digits stamped in the underside of the quadrant suggest that this specimen was manufactured in 1971. It is not known whether Millers Falls provided any other models of miter box to Proto.
Photos courtesy of Bruce Benedict.
And here is yet another specimen, circa 1980, in new unused condition. Photos courtesy of Kevin McDonald.
A Langdon Mitre Box Reference 