Question whats on the edge of your headbox? it looks rounded and shiny and not the usual ply

Answer: It's 19mm black plastic tee molding with the tee cut off and glued on with contact.
Now that I have a router, I do it properly.
It's a lot of rooting/routing? around but the result is pretty tidy.
You can get 3/4" (correct width) Black, Chrome & Red by the metre from madmat0077 on Aussie Ebay
or just plain black 19mm (0.5mm OS) from a shopfitting outlet.
I gather from your avatar you also have a TOM . . . WONDERFUL machine "the theatre awaits!"