I took an angle grinder, fitted with a wire brush, and cleaned the repair area to get a better look.  What a mess!  It looks like they tried to weld, then it looks like there was a little brazing too.  We watched YOUTUBE videos showing the lock and stitch method which we thought was a great idea, but I'm not sure this is going to help in this situation because the crack isn't going straight through.  It is going in at an angle - like the metal is laminating. This could just be the metal that was welded on the cast iron.  I will need to grind all of that away without damaging the original cast iron block just to see what the original problem was.
  Jennifer and I discussed this, and what we need at this time is to get that engine working long enough for us to check out the transmission and hydraulics. I'll braze the leak for now, and if we can get the motor to run, we will check out the rest of the tractor.  If all else is good, I would like to pull that motor and grind away all of the patch material and weld. or Locknstitch it correctly. If not, then we will just get another block.
  Hay - what the heck, its all fun, right?