I realize this is an old thread, and a long-shot at getting a question answered, but thought I would give it a post anyway! First off, let me say this was very interesting, and well done, restoration, especially for me since I currently own a Checkmate Eluder also! Bought mine new waaaaay back around 1980. Mine is black and silver and still in pretty solid shape, although it could use a good cleanup, buff and wax. It still has the original Mercury 175 on it!
My question is for the original poster (metriccrescentwrench) concerning the installation of the "in-hull transducer" (I believe it was in post #14 ), I assume the transducer was for a depth gauge, or something similar. I would like to add a depth finder on my Checkmate, and would like to do the in-hull/shoot-thru-hull type also. Not knowing the thickness of the Checkmate outer skin layer, I am a little apprehensive starting the cutting and drilling installation process. I won't be able to get mines as close to the transom as yours appears to be (I don't currently have the decking and tank removed) but I hope to be able to create an access area under the rear seat.
I was wondering how the transducer actually worked after the boat was returned to the water. Also, it would be good to know what type of transducer was used, and for what type of depth finder.
Thanks a bunch in advance, and Kudos on an awesome restoration!!