Dating campagnolo components
There is no compatibility between 2009-14 shifters and 2015 or later derailleurs.
For full function, 2015 gear shift systems should be used with 2015 crank sets as the spider and chainrings are designed to be much stiffer, facilitating a better upshift in combination with the redesigned 2015 FD cage and actuation.
A: In order to determine this, you need to refer to the Campagnolo Technical manual for the applicable year.
Also required is the drilling through the body of the lever at the top left of the right hand lever to accommodate the mode shift buttons of the system, and top right of the left hand lever.
It is to gain these drillings that the bodies of these mid-range ergolevers need to be changed for the Record / Chorus items.
Some other internal parts also require changing, as EC-RE631-based levers have some dimension differences in the central pivot around which all the other parts rotate.
The versions of Ergopower that either are, or can be made, Ergobrain compatible are identified by having a thumb lever that allows multiple shifts (rather than the later "Escape" type, post model year 2006 in Xenon, Mirage, Veloce, Veloce Infinity and Centaur).
Bear in mind that these characteristics can vary from year to year.