This was extremly easy to polish up just dressed the rough cast spots up, light media blasting, heavy scrubbing with with fine steel wool, than held on tight and let the buffer and rouge do the shinning up (used a loose fabric wheel so it could get into the fins and tighter areas a little better).
Messing with a Tecumseh block right now, It polished up easy too. but not sure If I am going to go with that or paint it (gotta do a mock up with the white shroud pieces to see how it looks all together.