How did you replace the inner gasket without removing the cover? If you replaced the perimeter gasket with the updated part and left the "old", inner gasket in place, you will soon have oil flowing down the inside of your jug.
I prefer not to grind or cut my tools unless it is absolutely necessary, which in this case, only required more effort and time to lower the engine.
let me rephrase, "This is no way to replace the rear rocker cover gaskets properly without rotating the engine, unless you start cutting welds."