I designed this with 123d beta - similar to autodesk inventor.
This mount is for a Sells Mendel and has the wade's mounting holes - I measured everything with a caliper to figure out the correct measurements :)...
Printed pics within the hour..and I will report if it has correct measurements or not. (I'm printing with a slightly incorrect mount right now with these linear bearings and they work a treat! - So smooth)
You will need 4x SCE8UU linear bearings and M4 bolts and nuts.
Search ebay for the linear bearings (worldwide).