The double-archbar swing-motion truck used by the Canada Atlantic, Grand Trunk and various other railways.
You'll find that the brake beams probably need straightening when they arrive on your doorstep, but will bend back into shape with a little coaxing. Don't try for a sharp bend as the material will break.
This model is optimized for the NWSL Proto:87 wheelsets on 1.015" axles, but should work with HO wheels as well. The sideframes have been widened to allow for the longer axles.
For more photos see flickr.