Jim, One of my magnets broke and I sourced some early Ford motor and gearbox units, I think from a Mustang, they were close enough that I was able to make them work by adding some spacers and welding up and relocating a hole in the mount plate
Thanks Paul. The drive gears are stripped inside as well, and although it appears the gears may still be available in Brazil, I have been warned that they stink. I am hoping to install manual operators instead.
I have looked at modifying the existing quadrant gear and lifting arm from the electric window system. I have considered fitting a manual crank and gear to engage with the quadrant gear and therefore allow for removal of the electric motors. It looks like it could be figured out without too great a difficulty. This would keep you away from the stock pulley and cable system.