Re: ‘40 right mirror
I mounted a small blind spot mirror on the passenger side wind wing. It's not an ideal solution, especially in cold weather, but it does help.
Just a tip. When you disconnect the cable from the speedometer, immediately cover the end with a plastic baggy or some such. Those things tend to have a mind of their own and can leave skid marks on your kick panel and/or upholstery when you're pulling them out. No need to ask how I know.
My dad flew the civilian(Stratocruiser) version of the KC-97 for Northwest. Fortunately, he never had any gear problems or lost an engine. As he said, he made it a point never to take those trips. I do recall him saying that you had to watch the temperature on those big R-3350 engines.