im not quite getting what u said lol here is a pic of the top
shane (confused)
Often the easiest ways to determine what sort of shape a flat piece of material needs to be to fit a three dimensional object is to make a
paper template or model of the object and then lay that template on a flat surface. This then is the shape you must make to have it properly fit the object.This works well for object with relatively modest concavity and/or convexity, like auto windshields, and, ta da, conics.
In this case the object is conical with a bit of a lip at the top. If you made a cone of
paper that fit snugly around the base and the lip you'd pretty much have your pattern to layout and cut your vinyl. You can deal with the recess under the lip by stretching the vinyl that little bit to conform to it.
The simplest way to do this is take a sufficiently large sheet of
paper wrap it around the drum so that it contact both the base and the lip of the area in question. Then mark both the base and the lip of the object on the
paper. Lay the
paper flat and where you marked will describe the shape you need to fit the object.
It's not rocket surgery.