Re: Filling a gauge hole
Please take my advice for what it's worth being that I am still quite new and in the early stages of my own restoration, but I would venture a guess that the BEST way would be to build it up with fiberglass. For my own project, however, I am planning on filling mine with marine filler/peanut butter, sanding smooth, and painting. Though my holes aren't quite 4" (my largest is maybe 3").