You were spot on with your assessment of the problem Bigted. Took the expander out, reassembled and it is turning over freely by hand. Can't thank you enough. smile Checked all tolerances and re-oiled.
BTW the min ring gap was .008 (not .08 as mentioned above) to .017 max, they were wider than .008 but still below max.

Couldn't find a torque spec on the flywheel nut, undid it with an impact gun...

Have also got a nice healthy spark by turning the engine over with a drill (after turning the coil around the right way blush ).

Will be able to go on with the rest of the rebuild now.

yay

Cheers.