I need the "thingy" that goes through the bottom of the transom on an alumnium 12' boat that the transom plug goes through. It would be a plate (I assume alumnium) that is afixed to the transom with a 5/8" hole for the drain plug. The transom looks like this:
This image was shot from the inside of the transom and this one from the outside:

This image was shot from the inside of the transom and this one from the outside:
