If you have a table saw, you shouldn't have any problems.
One suggestion would be to cut a saw kerf into one of the
strips just a tad deeper than your metal is thick so when
you join the two halves together, the metal skin will not
be visible on the top of the gunwale when you are all said
and done. There are several tricks to hold one piece into
place so it won't move while attaching the mating piece.
After assembly, you will have a very professional looking
wood gunwale.
Warning: do NOT - "
NOT " - use silicone or any products
that contain silicone to marry the two together.
IMO, silicone actually promotes corrosion. I have seen the warnings
on the tubes of construction adhesives that clearly states:
do not use on aluminum.
Read, Understand and Follow the instructions for any products you may use.
.