When creating the other colour pieces, I appended another bishop and pawn. I felt it would be better for me to build up rather than rework everything, so I added materials and parented a new pawn and bishop, then duplicated.
Duplicating the pawns wasn’t hard really, I just go " ALT D, Y, 6, enter" a few times. Takes just a few seconds.
For the bishop, I created a separate save file where the modifier WAS applied. So I have 2 saves, where 1 had the modifier applied but everything else is similar. I felt I didn’t want to bother with a notch in the final set up. If need be I could make changes in the unapplied save then append a new bishop.
I made the pawn empty 5 cm (coincidence it’s the same scale Mike went with) but the other whole empty 10 cm so I could tell the difference.