They look like late sixties NASA style flat pack NOR gate IC’s with hi-rel pins. Maybe early RTL.
Yes, Heathkit had some weird ideas in the early seventies. They had Molex make special staggered pin 0.1” IC strip sockets because the engineers in Benton Harbor were afraid Joe Six Pack couldn’t solder in-line pin sockets without bridging pins.
The original product was stamped and formed tin plated flat strip in roll form. You cut or snapped off strips of 7 or 8 pins, times two, and inserted into the pc board and then soldered. Once in place, you snapped off the top the held the pins together. They were absolute junk and they abandoned the idea as kit chip counts went higher and the sockets starting being the reason properly built kits didn’t work. As TTL became mainstream and cheap sockets hit the market, they went with custom one piece sockets with the same stupid offset pins.