Not sure about the technical name, but.....

[Skools Out]

that plate you have that's rusty is actually a part of a kit you buy called Bow Lifting Eye Kit. had one on the 21 i'm redoing currently. Took mine off too.

here's what you have it you want to just buy a stainless replacement. look at this link

http://www.foreandaftmarine.com/Bowliftingeyes.htm