Bob Allison
John,
I have built about 50 turnouts using a modified Exactoscale gauge that has only one flange at each end. One simply pushes the check rail gently against the flange at one end while holding the gauge fairly firmly against the opposite rail. Sounds awful but in practice it is ever so easy. And it avoids the problem reported elsewhere of the grooves forcing the rail into a vertical position, with consequent gauge narrowing when the gauge is removed and the rail adopts its 1:20 slope.
Bob