Driveshaft reassembly for 1966 Evinrude 3 hp

[boat123boat]

Replaced the impeller but the drive shaft won't go back together properly. The lower unit won't seat against the lower end of the leg properly. It appears that the shaft is cocked a little. Never had the power unit off and the shaft, impeller and lower unit assembly looks OK. The prop turns the shaft fine. It is as though the upper end of the shaft is entering the bottom of the engine at a small angle. Any advice would be much appreciated.
Jerry Schneberger