Yes it is worth something to the person that really wants one, I removed mine and went railless.
Rusted pieces, it's now a parts motor. Don't worry about them. Maybe scoot some oil on them, just because.
The motor may or may not be set on the backsplash, depending on the best performance location. That's normal.
Looks like Marine Tex should fix these.
And as far as for this
Here is your special paint
Here is a better picture of the serial # plug. This is on a 75hp Mariner.
Well maybe not the Mariner (I can't remember) but you get the idea.