Originally Posted by mcollinge
Good advice. Thanks!
One question, though: Why a level? How will that help?
I would use a level to check that the floor or table is level.
Then if the floor or table is level, you could just see if the the drum sits flat or if it teeters. If it wobbles on a flat surface, that is probably not due to the bearing edge, but due to a warping of the shell.
if the drum is warped but only in horizontal plane, you should be able to tell by using a ruler to measure the diameters in different directions. putting a new head on it might also be a way to check.