This would appear to be an ex British Railways 'Handiprinter' machine. Not for issuing travel tickets but for parcel stamps. Have a look at the document in this link (You will need Adobe PDF Reader or similar) :-
Figure 109 on P2 of the document shows a 'ticket' produced from one of these machines.
Have you managed to get it to print anything? I think they were only in use at a few locations in the late 50's / early 60's and were not a great success. Unlike their siblings that BR used up until computerisation in the late 80's for travel tickets at many locations mostly on the London Midland Region. Although BR would have termed them a success, I doubt this opinion was shared by any booking clerk who has had to use one in anger. I remember a Ticket Inspector once commenting that he could clear a queue of passengers by issuing handwritten tickets from a pad, twice as quick as a clerk with a Handiprinter could.
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