Good afternoon to you all. I am a newbie at this site and I must say I've been kind of lurking for a couple months but finally took a dive to sign up today. I came in possession of a Federal Signal Model 19 Propello Ray and I must say I'm still in disbelief of owning one. I got it as a barn find & it wasn't tested. I received it on Saturday and I'm still amazed how clean it still looks (some basic spit shining is all it really needs). My main concern is that there is only one wire coming from the bottom of the device and there is no second wire so I cannot confirm if this is the positive or negative. I attempted to open it up by first removing the brace that holds the faceplate up, but it appears to be rusted through (Image 1). I then noticed three screws that I believe holds the red glass but as I attempted to remove them, they feel stripped but I still cannot remove them (image 2). I would like to know what these are for if anyone knows (Image 2). I kept exploring & noticed screws on the base of the Propello Ray and not sure if this is how I can get in (Image 3 and 4). I don't want to damage it as it is a rare piece of technology and a lot of people want to see it run again. I want to try & get in to it, clean it, add new wires and test it. If I need a new motor, I will do some more research & find a similar model and then try it again. Any and all help will be very appreciated so I can open it up and get inside this beauty. Thank you for your time.