When I joined the LMR in Crewe in 1976 we used to send copies of special loco, unit and traincrew workings out via a reprographic department. We would stamp the master copies' serial numbers on with a device which notched up one each time (or every second time if there was a reference original kept.) They had their own ink pads in the mechanism... I don't think mine had "LMSR" on it but it might have dated from the '50s!Machines or "rubber stamps" for franking/embossing/stamping paperwork. Old fashioned post-office counter staff tended to have a very assertive way of stamping documentation as I recall.