I still have my 1965 issue Dalton that has seen much use. By far the fastest way to do unit of measurement conversions. I also have (somewhere) a Meer’s slide that was used on the V-Force to ascertain the corrections for speed and heading changes during Astro. There was another Astro related slide as well, iirc used for more esoteric activities such as Polaris homings. In a later life a RN Observer on helicopters showed me a Dalton slide used to calculate the jump distance for active sonar searches.
It was a very versatile piece of kit.
YS