damn steve... quite the group of lookers in your family.... well... 3 outta 4 'aint bad
:P just kidding dude...
something you can try... get yourself a sharp circle punch... or circle cutter of some sort... cut out the numbers on the tach and, if the cuts are made perfectly, spin them 90 degrees CCW.. if they all have the cut, then it'll be pretty uniform, and if the cutter is sharp enough, you may not even see the cut....
that is, if you've got the balls to cut up your tach :P