It might be heretical but clearly the "spot" in question in the photo was built for the set up you have. IF it's been working for you, just go with it again if you replace stuff. I would take it apart, remove the thru hull, look it all over, whack it a bit with a hammer, look for signs of failure, rebed or bed new and properly install that system once again just as it has been.
'Nother ten years of satisfactory operation, so to speak, go with it.