Re: OLD Catboat.
Slickest system for dealing with seams that needed to be cleaned out was a light battery panel saw run against a batten. The German who showed me this was splining tight seamed boats, Sonders I think they were. He had some blades made up to the precise shape of the spline. Having recently cleaned deck seams back to bright wood, some of the fein tool devices are pretty handy. But then you'd be into splines. Most useful was the triangular carbide abrasive blade which was long enough not to cause problems. Most of the people who do this kind of a thing for a living recommended a router with some guides and a small plate run against a batten.
Ran Tan, Liten Kuhling, Vernon Langille, Josef W., Merry Mouth, Imp, Macavity and a quiver of unamed 'yaks.
"Bound fast is boatless man."