How to identify mutual inductance?
You can use an inductance meter and connect the two windings in series. The configuration with the higher inductance has the windings connected dot-to-no-dot. 

The actual mutual inductance is the half the difference between the sum of the two inductances (measured separately with the other winding open) and the total inductance with the coils in series and phased as above. In other words if the inductance of one winding is \$L_1\$ and the inductance of the second winding is \$L_2\$ and the total inductance measured with the two in series is \$L_X\$ then the mutual inductance is M = \$\dfrac{L_X - L_1 - L_2}{2}\$.

By shorting one of the coils and measuring the inductance of the other (preferably with an instrument that gives you an L+R measurement) you can get a measurement of the leakage inductance. 

Of course the placement of the dot is (usually) arbitrary- if you reverse the dots on all the windings it is exactly the same thing for a typical inductor or transformer (there are some types of inductors that are magnetically pre-biased so the are not symmetrical).