I’ve never been that excited by his books, especially not by the style. His magazine articles and columns are different. He was connected with MITS when I first saw an article by him in 1971 in Popular Electronics. Model rocketry I think it was.
But then the first book about electronics that I owned was “How to Become a Radio Amateur” in 1971, followed shortly by the ARRL Handbook.
By the time he started writing those hand drawn books, i was well beyond beginner.
Don Lancaster’s books were always better, but often duplicated what could be had in databooks.
I think I still have an issue or two of the science project magazine put out by Gernsback publishing about 30 years ago, and edited by Mims, it was called “Science Probe”