The slight bumps on even a good brick are going to throw a torpedo off a bit.. They're only a few bucks.
Very true. A technique I use to approximate the base of a torpedo to a "real" level ,I glue two pieces of straight grained cedar cut to width of "regular" levels. Doing so insures that when or if you switch over in size,the reading corresponds. I use PL premium glue,lasts forever.