I know I shouldn't double-post, but this is a considerable update:
All 6 character shapes are finished, though I may go back and redo the Knight at some stage.
The back-face culled wireframe has also been replaced by the flat shaded polygons, so now I need to experiment with the board layout.
I know it only runs at 10fps, but when it's finished it'll be an almost static chess board, so it'll only need to update the graphics when the pieces are moved.