Mitch I can honestly tell you that in the 4 years I was associated with Lowe, we didn't use a hammer to fit anything other then on occasion to insure a good fit on carpeted hatch covers. They did use soft hammers on them sometimes because of the carpet. You can't hammer fit aluminum becasue customers don't like hammer marks on their boats. You should hear the beat down over a rivet gun slip. That's a small circle, or heaven forbid two. What you probably saw was soft hammers being used to seat extrusions, like gunwales, etc.
J-Doc the Pad hulls are stable on turns, they don't need the keels, striations to you, because of the bite the pad gives. Most glass BB's today have a pad hull and they've been around since the 70's. You also don't normally need a gasket for a hatch, and that isn't just Lowe.