Bob, years ago when we ran solid shafts we used needle bearings in the shaft log
We held them in place using another brass tube that fit the ID of the shafts log between the bearing thus holding them in place. Easy to change bearings
BTW one can put TOO MANY BEARINGS IN THE SHAFT LOG.
Any thing that rotates has a SINE WAVE.
If the shaft is held to ridged the SINE WAVE energy will be dissipated at the prop snapping the stub/prop off.
The shaft becomes like a bull whip
I saw this phenomenon happen several times in the days of solid shafts. Even MR GEE solid shafts