The new piston rings finally arrived so fitting commenced
Unlike most engines, the piston needs to be fitted to the conrod before assembly as the conrod remains fixed to the crank. plus the fact there is very little room to get to the gudgeon pin/clip once the barrel is placed over the piston and rings.
Also unlike other engines, when fitting the piston it is sandwiched between the barrel and crankcase again limiting the space to work.
A simple block of ply under the piston stops it from retracting back into the crankcase when the barrel is placed over it.
The piston ring compressor is a special tool because there is little room and a standard ring compressor will not fit.
Both cylinder are now back together.
The engine now spins over with plenty of compression so starting it shouldn't be an issue.
Just out of interest, the only gaskets and new seals needed in this top end rebuild were 4x valve steam seals, 2x seals at the bottom of the pushrod tubes, 6x brass washers under the cylinder head studs, 6x copper washers on the rocker oil feed pipe, 2x gasket under the rocker covers and finally 4x manifold gaskets!.