I used desktophero3d.com to build my own set of Cluedo/Clue board pieces (for the characters only). They are scaled to fit nicely onto 1x1cm board blocks. If you have a board with bigger or smaller blocks scale to size. The females are 0.2mm larger than the males - dont ask me why, it looks proportional thou.
Hope you enjoy. Feel free to comment or tip if you like.