Speaking of Ferranti and programming mothers : my mother talked about how she had been a programmer of a Ferranti Pegasus before I was born. She worked for an insurance company but talked about having to travel across town to an engineering company to use their machine because theirs hadn't been delivered yet. Based on her recollections they were coding in assembler. She moved on to pursue a career in economics and never coded again.

I found an article about the computer being delivered to the engineering company in 1960. The Pegasus was a mid-50's design (afaik unrelated to the Mk1) so I'm not sure if it was new or recycled from one of the initial customers.

https://www.electronicsweekly.com/blogs/mannerisms/memory-la...

https://en.wikipedia.org/wiki/Ferranti_Pegasus