Well Miles your first attempt was better than mine. I did make a sledge for my bandsaw but there was some play in it, too much it turned out so the joints were gappy. I was trying to insert plastic of different colours, getting the kerf just right even doing a second cut, just did not work. So now I am going to use a chop saw, the kerf on it will take three pieces of the plastic, two whites and red or blue, or go the whole hog red white and blue.
You already have all the advice, and so do I, so lets get going! 
