Thanks Gambler smile. I saw a couple of videos where they used the hammer to cut the paper, though I'm pretty hesitant (at this stage of my experience) to do that in-case I do damage the case, so I was leaning towards the drawing and cutting of it.. though how easy for it to damage the crank case with light taps ?

Also, regarding thickness.. is there a general rule-of-thumb or a usual universal thickness that can be used ? ie. One thickness can have multiple uses, not just for Crank-case gaskets etc.. ?