This is the X carriage from the Prusa I3 Mk2s github which has been modified to use the 46mm rod spacing of the Anet A8 instead of the regular 45mm. This should allow someone to print out the Prusa Mk2s extruder assembly and use it with the A8. Prusa's files are at https://github.com/prusa3d/Original-Prusa-i3 but make sure you have the MK2 branch selected.
25 March 2018: I uploaded a new .scad and .stl file. After printing a test version or three, I got the spacing right (for my printer, at least) at 46.2mm.