When I first discovered shortwave radio in 1959, Allied Radio in Chicago was my main source of information, like Amazon is today. We never drove up to Chicago, so I was never in their store, but they sent me one of their catalogs and I spent a lot of time looking through the huge variety of electronic stuff they had to offer. I bought my first ever kit from them in 1959, a Knight Ocean Hopper. I don't think I even knew about Heathkits at that time. I built the Ocean Hopper myself, my first soldering ever, and it worked great from the first time I ever turned it on. I spent hundreds of hours listening to shortwave broadcast stations from all over the world with it: Voice of America, the Canadian Broadcasting Company, Radio Moscow, a station from Quito, Equador and many others. It opened up a new and magical world to me. Eventually I stumbled on to the ham bands and that opened up an entirely new world and a lifelong passion and hobby for me. The earliest version of the Ocean Hopper was advertised by Allied Radio in 1941. Heath didn't begin their kit business until 1947, but they eventually became the biggest kit business of all time.
There was a long interview of a long time Heath employee that was published recently. It is very interesting and well worth the read, as Heath was a very important company in the history of amateur radio. I recommend you read it. Key Point - "Probably the single greatest lesson is focus on customer service. Heath lived by “We will not let you fail.” Even before this slogan was formally introduced, it was the company mantra."
Chuck Penson, WA7ZZE, wrote three guides to Heathkit products, all very highly rated. You might also want to check out his guide to the Titan II Rocket, the most powerful ICBM America ever built.
Classic Heathkit Electronic Test Equipment  by Jeff Tranter.
The History of the Heath Companies and Heathkits: 1909 to 2019 [2019 PDF] by Erich E. Brueschke, KC9ACE and Michael Mack.
April 20, 1995 interview of Steve Jobs in which he discussed Heathkits in the first seven to eight minutes or so of the video. He also told a great story a bit after that about his fourth grade school teacher.