The camshaft timing seems to be right by a simple tooth count.
The key may have wounded the crankshaft oil seal as well as the main bearing, plus I don't know what the final status of the crankcase cover gasket will have been after removal and re-installation. Also, if the tappets happen to have been put back into the opposite positions (intake and exhaust interchanged) the tappet clearances may be quite a way out.
I'm not confident yet about whether there is end thrust on the crankshaft due to the clutch cotter pin adjustment, which is why I've asked for the engine to be removed.
Once we work through these points, hopefully all will be well - but I don't yet know the cause of the rotational stiffness, unless it is end thrust on the crankshaft.
