I made a couple of gasket scrapers by grinding one end square then bevel like a wood chisel then sharpen it , Once sharp I hone the flat side so there is no burr and this takes the edge off a little so it does not chop onto the gasket face,
We used to make special knives for trimming the lead tape we used to mask jobs when I was in the Electroplating Industry.The most common was to grind at 45deg then sharpen so it was like a large craft knife , others were just like a normal knife but because they flex they were used to strip off the plastic wrap we used to mask large items .
We just wrapped the end up with insulation tape (also used as masking tape ) to make a handle but these days I use heat shrink tube .
Ian