Puzzle Chess Board - Remix

I downloaded the Puzzle Chess Board by pbreeden0 and started printing. I really liked the simple chess pieces and the board design was pretty nice also.

However, when I tried to connect the board pieces I realized that the nibs and holes were designed with the same diameters. Now I would like to think that I have a pretty good 3D Printer, but my modified Printrbot Simple Metal is a bit over 5-years old, and the original print tolerances of this machine just don't like holes & nibs to have t