Don't know what the part is called, OMC??

[JonEaton]

I need ONE MORE PART before the boat is complete, I have a 78 OMC 400 sterndrive with the ridiculously large transom seal, and the boat used to have a plastic piece that went around it to keep muskrats from chewing it and sinking the boat, what is the name of that part and where would I find one?

thanks!
Jon