I also have some early Craftsman 12" table saws which have a 5/8" arbor. Those 12" blades ARE difficult to find in all the various tooth configurations.
Bill, as you may remember, I have the same 12" Craftsman TS as you, with the 5/8" arbor. After reading your report about the scarcity of 12" blades with 5/8" arbor holes a few months ago when I joined WWT, I decided to see what was actually available... especially since, in my opinion, Sears is headed for dissolvement within the next 5 years. I found at least 20 different 12" blades, with all different grinds, kerf widths, and teeth counts, on the Forrest website, and 5/8" arbor was the STANDARD bore size, not the exception. Folks who want the bigger bore had to pay extra.
The key is to select all the 12" blade part numbers that are appended with A. I stopped counting at 20 different blades. For 3/4" arbors, there is an $11 charge. I'd consider that reasonable, given the importance of concentricity.
As for the Davis and Wells saw under discussion... Tool Agnostic suggests that there are no miter slots in the table, but I see two miter slots in the table, one on each side of the blade, in several of the photos posted by Christmastaco. Am I imagining them, or does anyone else see the miter slots also?
This looks like a very well built, and well taken care of saw. The $800 is also buying a lot of accessories, such as one of Delta's best fences, a router table, a cross cut slide, a rolling base stand, and a clean table. If I were considering this saw, I'd ask the seller for a close up photo of the motor tag, in case the seller was mistaken in his description of the motor specifications. Sometimes people don't read the details, because it is easier to simply rely on what they've been told. This may be the case with the seller, who for years may have relied on statements made by the salesman who sold him the saw, without every really verifying the real deal for himself, because the difference was irrelevant if he hooked it up to 230v from the outset.
Consider the value of the package, and the cost of what it would take to bring an equivalent cabinet saw up to the same level of immediate use functionality, either in the purchase of the additional accessories, or the cost in time spent on restoration. With those elements factored in, it appears to me like the saw is being sold for $400, because it would take at least $400 to bring another saw sold alone up to the level of condition and creature comforts that this saw already has good to go.