I am going to make floors for some of the American Flyer freight cars from  .040 clear styrene sheet. By using clear I can see where to drill holes for the 2-56 mounting screws which will attach the floor to the body. I will epoxy short lengths of plastic tubing in each corner of a boxcar which I will tap for the 2-56 screws. When everything is lined up I will paint the floor an appropriate color. I would imagine I could use the screw holes in the bolsters to mark the floor so as to drill and tap to accept a truck mounting screw.

I recently purchased a package of 3 Bachmann On30 underframes on Amazon.com. I model in S scale and these should work fine to add underframes to older American Flyer cars I am converting to scale. Does anyone know where I can purchase more of these as I have need of more?  Also, does anyone know the size of the screws that are included with each package of 3 there appear to be 2 different sizes?
              Thanks much
                     Bob