Made a bit more progress today, smoothed off the JB Weld repair on the displacer piston, repaired the top connection to the radiator, started reassembly of the bottom half of the engine sealing as I go. My goodness that blue stuff gets everywhere!
I made a thick gasket as suggested. I had one piece of the thick stuff left which was just enough to fit, my gasket punches were having trouble getting through it I think they may be worn