e-bike selection
Like you I am ex aircraft industry and approaching 80. I converted a good touring bike by adding a 1000w hub motor to the front. After burning out my 1st motor I bought a later model and destroyed that riding Welsh mountains in Welsh rain. I concluded that the conversion was not up to my cycling habits. Besides the bike was festooned with wires and my pannier rack was overloaded with a large battery. The bike became pretty unstable.
I then bought a last year model Kalkhoff at sale price. German engineering shines through the whole concept. The wiring is buried and the lights are adequate. I have no trouble with 1 in 5 hills unless the track becomes too broken or wet and the wheel slips. As you will guess, I only potter about and so in mountains I have a range in excess of 40 miles and on flatter country I plan on 60.
The only disadvantage of a Kalkhoff is the height of the bottom bracket above the ground. For this reason I recommend a step through frame as opposed to diamond frame. These machines cost much more but they are robust and reliable.