Although most classic boats were built without them, I would not consider restoring one without adding an ignition protected blower to the engine compartment. For a gasoline-powered boat, this is a necessary piece of safety equipment that can keep you from accidentally blowing up your boat. Originally you were advised to open the engine compartment hatch and let it air out for about 5 minutes prior to starting the engine. This might sound like it would work, but when you consider that gasoline vapors are heavier than air, it stands to reason they will just lay in the bottom of the bilge waiting for a stray spark to ignite them.
This blower will have an intake hose that pulls air from the bilge below the engine, and blows it out one of the vent ports on the afterdeck of the boat. Ignition protected bilge blowers are required equipment on any gasoline powered inboard craft built today. It’s not hard to add one. Why wouldn’t you?