$30 is definitely a good price for that. Since it has been sitting for the past 40 years, the hoses will most likely need to be replaced. The rubber tends to get hard and gets brittle. Being that this is a 60+ year old machine, the parts are hard to come by. You may have to do some creative thinking to figure out hoses for it. Not only local appliance shops but also your local auto parts store. I can't remember how many times I've taken a hose into Autozone for a washer to get replaced. When there they usually ask me what it is for. I get a weird look when I tell them it is for a washing machine.
You said you could hear it hum, did you turn the knob to see if the tub spins or the agitator agitates?
Towards the top of this page, there is a link titled "Manuals & Literature" It consist of owners manuals as well as service manuals for many different machines. I saw some early 50's service manuals for Kenmores. Wouldn't be a bad idea to download it. They do cost a little bit, but not much. You can use PayPal to pay for it.
By the way, Justin here.