[C320-list] Rudder Damage

[islgirl3 at aol.com]

I recently notice several rust marks on the rudder of the Barbara Rita. When I sanded off the paint apparently something hit the rudder. I found 2 dime sized dimples and a hairline crack about 2 inches from the leading edge. I drilled a few 1/4 holes and only a very small amount of water leaked out just below the crack/dimples . Upon sanding out the dimples  and the crack (to the foam) I noticed that it appears the rudder is lightly skinned ( no matting). 
Has anyone made similiar repairs?  See attached.

Rich NuzzoloBarbara Rita 897