Mystery spanner / wrench
 

Again, not a tool I know the use for

No markings that I can read but there is something on the handle that might be visible if I sand many layers of paint off

I feel it must go into something concave, a wheel or a pulley or perhaps behind something and hence the crank to the handle

Approximate dimensions by eye with a tape measure not a vernier

Again, it will go to the bin if no one knows what it is