REO started the Speedwagon name in the early 20s. It was the lighter 3/4 ton to 2 ton models, the idea that they were light delivery trucks yet a robust worker.
It could be that the REO logo decal on the front looks liket the Chevy bowtie. Or out in Alaska someone used some other truck parts to keep the REO going.
There was no Chevy "speedwagon", nor is Chevy or GM associated with REO. REO was a very respectable truck on its own. REO made their own engines. They were often a good choice for fire trucks and high quality commodity haulers.
Save the truck if you can, you'll have a nice one to work on. Parts are available if you make the right connections.