Re: Exceeding the max hp
I wouldn't sweat it, especially since it's your cousin, and not you, who gets the ticket.
There is a lot of bad information constantly posted here on this issue as to the "legality" side of not complying with the plate. You have to look at your laws in your jurisdiction. Nothing else matters; no one else's experience matters; no one's guess matters; no one's third hand rumor matters.
I am aware that in some jurisdictions it is illegal to change or hide the numbers painted on the cowl even if you are still legal. This happened to a duck hunter who painted his legal motor. it probably also involved a LEO who gives the others a bad name. This does not mean your jurisdiction has the same law.
Some jurisdictions incorporate the rating plate as what is legal, some do not. Some case law uses the rating plate as evidence, but not proof, of safe/unsafe operation. I suspect an insurance company would see it the same way--but what an insurance company does is a matter of contract--what is written in your policy, and not anyone else's.
When it comes to rigging and operating a boat legally, though, there is always the vague and unqualified "unsafe operation" rule that can get you. Like "disorderly conduct." No one knows what it takes on the close calls; we all know it when we see it for the easy cases.
So ACDC, consult Connecticut regs and also any regs for the particular lakes that may be under their own jurisdiction (like National Park).