There is a very good chance this isn't a mariner specific part.
In fact, it's very likely a common part across a number of small petrol engines. Motorbikes etc.
Had this with a Tohatsu solenoid recently. £60 for outboard part. £18 for a part imported from China (let's face it, the Tohatsu one was probably made there too).
My google of your part number suggests is COULD be a common part to a chainsaw.
