your best bet would just go to a store that sell delrin. look for a piece that's 1 inch wide .50 thick and 5 inch long. the sled should be about .75 long, .25 for the hole in the middle and .25 for the front and back. the gap between the leg should be .50.
the piece should be about $2.50 and u can make 5 piece being about 1 inch long out of the 5 inch piece just in case u mess up u have a few spare.