Hi Graham that looks a nice assembly, in particular the modified Phosphor bronze bushes, I see a joint in the drive chain, a lot of modelers go for a solid connector taking great care to align the motor and prop shaft, I personally think this isn't the best option, the reason being having done this myself and gone to the trouble of using a dial indicator to align the shafts in the workshop (workshop heated) I later went to the test tank (in the garage cold) and found the alignment was no longer ! this was due to temperature change when wood has a habit of moving around at different temperatures.
I'm sure that some sort of universal joint is the way to go, It may be with some types they are a little noisier but still probably not as noisy as a brushless motor anyway. I still go to the trouble of aligning the shaft and motor with a solid joint first and then replace it with an appropriate flexible joint.
As demonstrated in Grahams description😊