I ran your serial # at Genuine Mercury & Mercruiser parts and it is the one.
As BUP states many times, OE is the way to go on all electronic parts (i've been in auto repair since the dinosaurs disappeared) unless it is proven an aftermarket has a better design (rare!) for any part in question.

So, thus why I checked ACDelco as they are the OE manufacturer/supplier on these IAC's. Merc uses many GM parts in many of their motor assemblies for obvious reasons.

I will add that Mercruiser Makes its own T bolt IV / V distributor cap and ignition sensor right here in the USA. They make these parts and some others right in florida. Merc makes other electronics and plastic parts as well. Just and FYI

All the other ignition sensors on the market come from Taiwan and other marine ignition parts