Bergeron sells Aquamet shafts, in 19 and 22 depending on the power level the customers wants.
Denton, I use this setup from mc MasterCarr, and it works pretty well. Found a cracked prop with it, and have used it on parts I knew to be cracked previously just to test it.
http://www.mcmaster.com/#crack-detectors/=qje8ip
I would still consider wet magging the rudder, and the strut if and when you have them out.
The rudder needs to be checked around the area where the shaft meets the blade, and the whole strut should be checked.