Looks very clean. Not sure about the 502 V8. https://detroit.craigslist.org/mcb/cto/d/1974-olds-torondomiles-nice/6348664031.html
Wow, no door dings or ripples in that flank. The speedo problem likely is a disconnection or a bad gear in the tailshaft.
If the seller is correct that the Cruise control still works but the speedo doesn't it is most likely a bad upper speedo cable or the drive on the cruise control module mounted on the drivers side front inner fender. But also could be as simple as a disconnected cable at the speedo, or a bad speedo but the last one would surprise me. Good looking car even if the seller doesn't know what engine is in it.