Very cool - I've known of these folks for a long time, but never saw the pictures.
However, I just totally fail to grasp the wisdom of the "no computers" strategy. I am not sure how you run a proper business without a computerized perpetual inventory. I bet these guys could quadruple sales in a year with some modernization.
I've seen dozens of these kinds of NOS parts companies over the years. In a sad number of cases when the original owners passed or retired, the parts went to the landfill as relatives settled the estate. Many tried to find a buyer, but the deals fell through precisely because there was no reliable inventory record to enable a buyer to fairly value it or to line up financing.