Great callout, was going to drop by to make the same comment. 
For a project like this you should be all set with tabs and slots in Sketchup as in polarbrainfreeze’s example. @marmak3261 I believe was using that very plugin over in this thread to what appears to be great effect.
There’s some other pretty crafty projects out there specifically centered around board game inserts: Daedalus Productions, for instance, open-sources their designs if you’re looking for more examples.