622 is 700c, it is literally the most common diameter of road bike wheel you'll find. You shouldn't have a problem fitting 23x700c tires on there, which you should be able to easily find. Nothing custom about that size. Once again, this appears to be a terminology issue where someone took readily available rims, spokes, and hubs, and custom-assembled them into a "custom built" wheel, just like they appear to have taken a readily available bike frame, and "custom built" it by putting parts on it to match the rider's expectations/desires.
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Bikes: 1996 Eddy Merckx Titanium EX, 1989/90 Colnago Super(issimo?) Piu(?), 1990 Concorde Aquila(hit by car while riding), others in build queue "when I get the time"