Help! Need to attach a bow rail/cleats

[SGI]

I bought a used 18 cc, and need to put a bow rail and two spring line cleats on it. I want these to be bolted through the gunwale with backing plates, but there is an extension/overhang off the side (under which you store fishing rods and oars etc) that is attached by screws and silicon caulking. This appears to join the liner of the boat, just below the gunwale and I can't tell if when I take it off, there will be access under the gunwale to attach the bolts. Does the SeaCraft design not allow you this access? If not, any alternatives that will be strong enough to support stanchions and cleats? Any advice MUCH appreciated.