It looks like a "crinkle finish" machine, I think sometimes called a Godzilla finish.
I don't think the model is particularly collectible; however, it should be fairly easy to find a replacement face plate for the machine. It would be a nice machine for someone since it works, assuming the electrical cords are in good condition. Unless it's a collectible model, a working machine like this in a cabinet would sell for about $30 in thrift shops where I am located (urban upper Midwest).
There are vintage Singer websites online where you can look at pictures of machines and figure out the model by matching your machine to the photo. Isaacs is one good online resource for that.