Welcome to GTTalk. Given that the tractor has a lot of rust I would start by checking and cleaning all the high current contacts in the starter circuit. You also need to make sure you have a good connection from the starter/motor chassis back to the - terminal on the battery. Once you have verified the connections then but a known good, fully charged battery on it and try to start it again. If that doesn't work you need to do some electrical troubleshooting to find out where the problem lies.If you could post some pictures of the tractor you may get more help with identifying it and getting technical info.