If it makes you feel any better, it looks like a nightmare to me too. And I do this for a living lol.
You might surprise yourself with what you can accomplish. Working within the limits of your skills and tools, it might be possible to simplify the design and yet still arrive at a satisfying solution.
I’d suggest gluing a stack of plywood sheets, planing the edges flush and flat, then covering with an oak veneer edge banding. All you need is a saw, drill, hand plane, clothes iron and razor knife. Maybe a little sandpaper.
You can get 12" wide oak veneer edge banding on amazon for about 20 dollars in a 4-foot roll
…Just enough to wrap a Goban
Then outsource the grid pattern work. Sign shops usually have the ability to laser etch, CNC or print with very durable ink if you just give them a vector file of what you want on the board.
***You may want to have the design printed on your top sheet before adding to the thickness, since their printing machines may not accommodate stock that is 6 inches thick.
Couple of things:
Use Titebond 1 for your wood glue. Titebond 2 and 3 are slightly stronger and vastly more waterproof, but will inhibit stain and finish absorption if they get on any exposed wood.
Use true wood screws to clamp sheets together when you’re gluing. True wood screws have a sharp pointy tip, medium threads, and a smooth shank near the screw head. The smooth shank will pull wood pieces together much more tightly than a screw with continuous threading.
If you’re using 3/4" plywood, then screws of
1-1/4" length should be alright. Just enough to grab the next sheet, but not enough to poke through the front.
Space your screws about 3 or 4 inches apart across the entire surface and leave for 24 hours before removing them to glue the next sheet.
@cleinias Let me know what you think. If you decide to take this on I will gladly walk you through the entire process in excruciating detail.