Related: If you haven't seen this 60 year old US Navy training video on "mechanical fire control computers" it is definitely worth a watch. https://www.youtube.com/watch?v=s1i-dnAH9Y4
Came here to post this.
Fascinating. Thank you very much!
Ars Technica also did a good write-up on that subject:
There are some old coastal defense bunkers/stations along the SF coastline that were used for the same techniques. Except rather than a small rangefinder station each location would act as one eye in a network to provide even greater accuracy.