The filigree band on this cabinet is finished before it ever touches the cabinet, and that order of work is not negotiable.
Pierced work only reads as pierced if the ground behind it stays clean. Every opening in that band is meant to show ivory - crisp ivory, the same tone as the case around it. The moment silver finds its way into one of those openings, the piercing stops looking like lace over a pale ground and starts looking like a smudge.
If the band were applied first and finished in place, that is exactly what would happen. Silver would carry through the openings onto the ground behind, and no amount of care at the edge would prevent it, because the openings are the places a brush cannot see into.
So the band is carved, pierced, cleaned up and silvered as a separate component on the bench. The case is finished in ivory separately, complete and even, right through the area the band will cover. Only then are the two brought together and the band fixed down.
The band can also be removed for future service without disturbing the ivory beneath it.