No there's no new seam, the hole was fairly close to the middle seam, within one or two pleats of it, so I presume that they just unpicked the middle seam, cut out however many pleats needed to be deleted to get rid of the whole, sewed it back up and took some tartan from the inverted pleat to create new pleats. That's my theory anyway, here's some pics of my kilt if you would like to take a look.
Looking at the inverted pleat from the inside.
The pleat width is about 3+3/8"
I counted 26 pleats in total.













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