RCA-Roundie One Owner

[refill233]

Just picked this RCA up in a woman's basement that bought it new. She thinks it was in 1958 but wasn't sure. She had right down to the orginal owners manual for the set. The picture tube has been replaced. She couldn't remember when. Hasn't been powered up in years. The set is in great shape with all the orginal knobs. Its dirty and dusty as you can see in the attached pictures. Tested the pic tube and all 3 guns came up to about 8 just warming up. So the tube is good. Didn't go for the color set but bought it anyway. The top of the set slides off. Thats different. Now what to do with it. I'm in to early B&W not color. Anyway does anyone know the year for sure? The model number is in one of the pics.