My response:

Sounds like it’s a Conn stencil. At least a few companies would make ‘stencils’ which are saxophones with a different brand name on it. For example, I have a Buescher tenor sax that says “Carl Fischer” on it.

Stencils are going to be pretty much the same as the other saxophones that the same company made at the time. Just with a different brand name.

It’s probably worth about $350 (could be a bit more or a bit less) in good shape. Maybe up to about $600 if it’s in great shape and sounds really good.

The vintage American horns can sound great, I play them myself (Bueschers). If it needs repairs, not worth as much though. They can be more difficult to play compared to a modern horn.

In general, I wouldn’t suggest someone starting to learn to play saxophone on a vintage horn.

I saw this related thread on Sax on the Web, http://forum.saxontheweb.net/showthread.php?184380-Hamilton-Alto-Saxophone