I found this picture yesterday. It's not exactly the same machine but it's very similar, still on sale in 1940. The picture is from a catalogue of tools from Gardiner of Bristol. For a tool to stay in production that long the original design must have been sound.
View attachment 88393
But clearly there was change in the wind. If you were feeling flush with the cash and wanted to go all modern, you could get what looks like the same basic machine but with a big electric motor bolted on the top:
View attachment 88394
(Though tbh, by then you probably had to have a chit from the Ministry of Supply to say it was needed for the war effort . Just liking rugged old machinery probably wasn't enough to get the right permissions. :| )