Using the Al spinner from HK, I am not quite sure whether I have attached them correctly. There does not seem to be any other way, and parts D and E seem to be superfluous. Can U help please?

Bo43,
The blue washer would normally go between the spinner nut and a wider propeller hub - so the nut does not deface the propeller.
The small nut looks like an alternative if you don't want to use the blue spinner.
The long overhang is a bit of a worry, I would be tempted to trim the motor shaft so the prop adapter comes back against the front of the motor, with no open length of shaft. A long shaft like that will bend very easily (most HK shafts are made from an alloy of wet noodles and anonymous metals) and may even flex and vibrate airborne with a large prop and manoeuvring).
Good flying,
PeteM

Thanks Petem,
I will cut the motor shaft. It is in part threaded, the threaded part is in the collet. If I cut off the shaft, the remaining portion will be unthreaded. I presumably won't have to cut more thread on the remaining shaft to give a better grip in the collet?
Bob

The collet functions most effectively on a smooth shaft. The taper in the collet causes it to compress onto the shaft when the prop-nut is tightened. threads just cause the contact area to be reduced to a small line with incredibly high specific loading. This can potentially yield the soft metal of the collet and cause loosening of the assembly. The smooth part of the shaft gives better long-term grip.

Thanks, both of you. I still find part B in the diagram, yes, functional, but too long to be attractive. I have now chopped off 5mm of the motor shafts. In one case, tightening the collet did not avoid slipping, so I Dremelled the shaft to roughen it up a bit. Now all OK.
Sorry for the silly questions, but it is my first RC model, and I have never flown RC yet!! Terrified of the maiden flight and the programmed crash. My experience is more with Paper models (my site www.bobscardmodels.net76.net ) where my first model was the Canadair CL-415, my first love. Living in the S of France, these planes, with their slow speed and deep-throated engine sounds, in lines of up to 5 planes, water-bombed the bush fires. The one I have just finished, using my decals copied from the originals, I attach. Note: on the photo, the motor shafts have not yet been shortened!

Bob,
Glad you have sorted the technical difficulties (a spot of threadlock might also help if the shafts are slipping, also make sure that the shafts are not 3mm and the prop adapter drilled to 1/8" (2.18mm) - this can make a good fit near impossible to obtain).
But back to the reason for my post - please get some experienced RC help before you go flying! You have done a lovely job on the aircraft, and the probability of success with no model flying background is near zero without experienced help and instruction.
Off soapbox - enjoy your hobby,
Pete

Beautiful work with the CL-415.
I have only seen one, and was amazed how HUGE it is. It looked to be the size of a C-130.

Jim, you ain't seen the Martin Mars yet? With a wingspan of 60 feet and a water load of 40 tons!! On my site there is a photo of it next to the smallest, a 'Tracker'.