No, you should send that junk motor to me

I am betting that all 40hp Merc 4 strokes use the same cases and such so you should have bosses to bolt the starter to somewhere, I have an 01 25hp 4 stroke and it's mounted on the left front of the motor. Assuming the motor has the necessary bosses but doesn't have the toothed flywheel you would need to buy that too, so a flywheel, starter, starter solenoid and some wire if you are going to wire it in yourself or a Quicksilver starter box or w/e you call it for your starter wiring.
I am betting that will be pretty steep, you might be better off getting a used or even blown motor from fleabay for the parts.