Fred
   The 2 blocked off ports on the exhaust manifold should have 2 lines going to the intake behind the carb on the lower side. These tractors were designed to burn kerosene or distalate. These lines make the mixture go thru a chamber in the exhaust manifold where it is preheated during low speed operation. Some people mix gasoline with number one diesel fuel today.  
  I have some new oldstock belt pulleys and some other parts I bought on a sale last spring. I will sell some of them but the number I have is limited. I also have 1 or 2 pulleys I had cast and machined. The rear wheel lugs may be hard to find. If you haven't found a seat yet let me know and I'll check on one.
   If your tractor has the original magneto there should be a brass ground terminal sticking out of the breaker point cover. When the magneto advance is turned all the way to the retarded position the brass ground terminal is grounded out on the iron that holds the beraker point cover in place stopping the engine.  Hoov