Let's be sure that you don't hurt yourself or others. You said that you were going to a tractor supply place. Is that were you got your fittings for connecting the gauge? If not, are you sure that they will handle the high pressure of a hydraulic system?
If you are interested, send me a PM with your Email address and I can send you a couple of PDF files. One is the Starter disassembly and the other is the Solenoid.
I am not an expert, but it looks to me that that is the type of fitting that takes the 'rubber-wrapped washer'. Can't remember what it is actually called.