It helps if you can determine the turns/volt and this way you can wind the correct number off the bat, throw an extra couple on, you can always take them off if too high.
The number of turns is independant to the gauge. Measure first, take say 10 turns off and remeasure to get the T/V.
If you have them already removed, put 10 temporary turns on and to the same.
If connecting windings in parallel, make sure they are both wound together, not one after the other in order to get good balance.