Your particular bike was made by Murray. The long pointy rear dropouts was a signature design for Murray cruisers. As early as 1962 to mid 1970s. They sold the same bike under many brand names and models to different retailers. They used different serial numbers systems for some retailers.
About 1979, the Spoke-a-Roo reflector was the topic of a drawn out patent claim and subsequent lawsuits. Most are so brittle they will surely break if you try to remove them. Best to unscrew the spoke and slide the spoke out the clips. The older ones are red or yellow. By the late 1970s, the CPSC mandated that all spoke reflectors in the USA be white. that reflector may have been added later on.
I remember those bikes being lined up in front of the Holiday gas stations. Also sold at Western Auto car parts stores. Surely sold under many other brand names as well. A different name for each retailer. Made by Murray, Columbia, AMF, etc for any company that wanted to sell bikes during the bike boom. Yours looks to be in pretty good condition. Fresh rubber may improve the ride some. Rock hard rubber won't ride well on any bike. The tire size would be the same as modern 26" bikes. BSD of 559. 26 x n.nn. (no fractional sizes will fit). I've ridden some with knobby tires, just awful. The rusty ones I see are better used as yard art planters in gardens.
The cantilever frame kinda looks like a Schwinn design but the build quality is really lacking. The basic frame construction method is to drill a hole in the bb or head tube and stick the frame tubes into that hole and tack-braze the joint. I've had two so far where the brass broke letting the tube slide out. Just isn't very sturdy. If you pedal hard on these frames, the bikes flex like crazy and you don't go any faster. The fork ends are just the fork blades smashed flat and slot cut in for the axle. The rear dropouts are rather thin mild steel and bend very easy. Often the thin spokes are loose so the wheels wobble. All the bearing cups are stamped sheet metal. They were about the cheapest bikes when new. $29.95 in 1962. About 1/2 the price of a Schwinn.