Thanks for your reply.

This Arauco sounds interesting, what is the thickness and dimensions of this plywood?
Does it have voids, and a rough C grade finish. Or, is it voidless with a B grade finish, smooth for veneering?

I have been thinking about using some 1/8" oak flitches that were cut from a 13" wide board as side and back cover for these boxes. then use a darker veneer for the front baffle for contrast.

Certainly a box built of this Arauco if 3/4" thick, where I could butt all of the joints, would simplify life and make for a substantial box.

Your box design sounds like a good direction with the proper bracing.

I would think the window frame braces are made from the marine plywood? Did you laminated layers of this plywwod for the bace, or is it a single layer?

Did you use any special glue when gluing up the butt joints?

Any other specific information will be helpful to this carpentry newbie.

Norris