dpb wrote:
N8N wrote:
...

shim stock or shingles could be made to work but would require a lot
of planing/sanding, is there any wood product that you can think of
that is flat and 3/16" or more thick (but obviously not so thick that
it would require excessive planing/sanding when done) ...
...

A small piece of pine w/ decent grain and a (sharp) block plane will
make quick work of it.

--

And we have a winner! Don't over-think this, it isn't that hard. Square
up the hinge mortises with a sharp chisel, and cut a square-cornered
tight-fitting plug slightly too thick, and glue it in place. Maybe pin
it with a brad till glue dries, if you don't have a convenient way to
stack weights on it. I think I used Gorilla Glue last time, because it
was handy, but yellow carpenter glue is the traditional material. Resist
the urge to touch it until the glue tries, and then plane and sand. Once
painted, you won't even be able to find it.

--
aem sends...