Thank you for the replies. I hadn’t noticed that one of the wheels may have been welded to the axle. I will look at this closer later. If that’s the case, does that mean I have to replace the axle to replace the wheels? That would be a bummer because I do want to replace the wheels with something a little more retro looking. I have to imagine finding an original Clark pedal might be difficult and if that’s the case, I’ll probably just get one from the link Hellion provided. I’ll keep my eyes on this form and will post updates on this cart once I have time to start digging into it.
It sure looks like the wheel was welded on. However, looking closer and zooming in on the wheel in the last pic you see what looks like a paper-thin gap between the blob of weld and the axle. Maybe the wheel was welded first then drilled out to accept the axle to make it fit (Damn it, Bubba!)? Then of course there is a split pin/cotter pin on the end as if it was holding the wheel on. It really doesn't make any sense.
Another thing that looks wonky is that the wheels (or at least one of them) are one-piece style wheels for tubeless tires, but it looks like the tire valve poking through is for an inner tube, meaning it has inner tubes installed(??). Nearly all of these vintage rear engine karts use two-piece wheels (steel or aluminum) so these were added later and judging from the tire valve, are all kinds of wrong.
The first 5 photos at this link are of a "restored" Clark Cyclops with the previously mentioned Manco or 'Thomas Manco' style wheels made of cast aluminum:
https://www.oldminibikes.com/forum/index.php?media/categories/cyclops-clark.1514/
To be honest they look a whole lot nicer (cleaner castings) than the stuff you see on Manco fun karts.
Inspect all the tires for a brand name etc, they may be "vintage" or period-correct for the kart. Lots of go kart and minibike people have a kart/bike in their Man Cave with vintage tires installed (which may or may not be safe for actual riding) merely for the sake of authenticity.
You will have to do a thorough inspection to figure out what exactly you have in regard to its cosmetic and mechanical condition. For example, are the rear rims welded to the axle or not, that sort of thing.
Look for Manco style rims around the web. There's always a few on Fleabay but the asking prices are often a bit steep...