My father was the chief booking clerk at Chippenham in the early 1960s where Westinghouse was based. They had one of the first (perhaps the very first) machine installed. Come price change day, every single printing plate inside the machine had to be changed, a massive amount of overnight overtime.
He moved to Liverpool Lime Street where they had several machines which had different ranges of destinations which is why there was one booking window for 'Stations A-K & London' and another for 'Stations L-Z & London' (or some other ranges of letters)
Spot on. You beat me to it. I remember them at Birmingham New Street and Euston in particular because they were visible through the glass walls of these modern stations. But other stations had them - even Birmingham Snow Hill before it ceased to be a significant station in 1967. I have operated one myself. They came in 'long' and 'short' versions.
The 'top' had a huge inertia as the clerk slid it in two dimensions to stop over the right 'cassette' and hit print. Obviously if you stopped it in the wrong place you had a 'mis-issue' to account for. Each cassette had its own counter, I believe, and you could get an 'audit roll' print of the closing numbers.
The main advantage was avoiding pre-printing tickets and thus the large racks in which to store them. But they still had distinct limitations. Fare changes was an obvious one but 'unpopular' tickets without a relevant cassette still had to processed and accounted for by hand. With each transaction being quite distinct they were quite slow although you could obviously 'repeat' a transaction for a small group making the same journey. Some clerks might pre-print a few of their most popular tickets and have them by the window for instant sale but this was frowned upon.
The whole process of handling large amounts of cash, warrants, cheques and so forth was still very cumbersome. 'Slow' service and "you're at the wrong window" could easily turn into passenger complaints as currently being touched on in other threads about 'good old BR'.
A masterpiece of German electro-mechanical engineering but not really a breakthrough.