Actually Pretty Nice:
While there are some changes from original, that house is remarkably intact for one of that period. The late '60s and early '70s were very rough on those houses - a lot of people suddenly decided they just had to have Mediterranean furniture, orange (or avocado) shag carpet, dark wood panelling, vinyl kitchen flooring that looked (sort of) like brown-and-orange Spanish tile, and lots of ornate lamps hanging from chains. In my work, I've seen quite a few house owners spend very good money to get this 1950s look back into a vintage house.
What I find intriguing is the references to the previous owners living mostly on what the Realtor refers to as the "lower level." That's a basement, and if the family lived down there to spare wear and tear on the rest of the house, all I can say is that they took "house-proud" to an extreme I've never seen before.
Very interesting survival. My main reservation would be the replacement siding. There are also modern storm windows, but that's not something I hold against a house, because energy efficiency is a necessity today, and storm windows, unlike those horrid vinyl "replacement" windows, are reversible; you can remove storm windows without having done much damage to the vintage prime windows. Just a few screw holes.