That's interesting.  Good catch.  I would consider stainless screws in the correct quantity for deck hardware, unless you're really going for a classic look (and ignoring the modern cam cleat).  Regardless, cam cleats usually use flat-head machine screws (I prefer using oval heads) that mount down through the axle of each cam and get nylon lock-nuts with washers underneath.  If you can't get to the back side, then you gotta do what you gotta do.

I am confident CLC will give you the correct number (3) screws for each swivel cleat.  I purchased the same upgrade for the NE sloop rig and was pleased with what was delivered.

More importantly, you need to look at how how you manage the mainsheet reefs and jib for solo sailing.  I rigged mainsail lazy jacks and furling jib for my sloop rig NE dory.  I was very pleased with its performance, however I moved onto a Caledonia Yawl by Iain Oughtred.  I built this boat with the balanced lug main and mizzen.  This boat is a great open day sailer that can handle more passengers safely, and at the same time out perform any NE dory configuration.

I know this from first hand experience from sailing with friends who have NE Dories.

Sorry to post such blasphemy on  the CLC website

Timber Cruiser --

Those swivel cleats do take three screws each.  IF I had a complaint about CLC it would be directed at the person who bags the screws.  Coming up short -- or sometimes long -- on screws was the bane of my NE Dory build.  As Captain Skully noted, stainless make good substitutes especially if you can't get good bronze screws locally.