If you don't already know about it, you might be interested in "From Dits to Bits", the autobiography of Herman Lukoff, an engineer who worked with Eckert and Mauchly.

It's hard to find these days, but a competent university library may have a copy (where I read it). This ref may be helpful: https://dl.acm.org/doi/book/10.5555/539966

A quick link to his papers: https://archives.upenn.edu/collections/finding-aid/upt50l694