One thing I staretd doing came from your same problem of not wanting to drill holes in my boat, or more than I needed. Granted my 02′ aluma 165 mag aint nearly as nice as your new raft.
But i mounted a “base plate” for the thing I wanted to attach. I have or had a bunch of 1″ plexi that i cut squares and mounted the square to the boat and mount mu items to those squares. When I change my set up i can just make a new base plate if i cant cover the holes from the old item. ie. going from a lowrance gps puck to a humminbird puck. I inagine Aluminum would look nice too, enpicially with chamferes edges (45 deg. angle routerd edges)
In the pics Ive got a my down rigger plates mounted this way. above the guage panel is the best view i had on file.
Just a thought…
–Mark