Was the strip screwed to the form and then later
: filled with a plug of lighter wood? I like the look it gives to the shear
: line.

Yes, I screwed the first sheer strip for both deck and hull onto the forms with drywall screws through little pieces of wood (to protect the strip). I remember Spidey recommended this on one of his posts. I'm glad I fastened everything down well to start with as nothing shifted later and it was quite easy to tape the next strips in place properly. After stripping, I just enlarged the holes slightly and put in basswood plugs for the deck sheer strip, and mahogany plugs in the hull sheer strip.