There is no postwork to the figures in the promotional ads other than composition.
Texture expansions for Betrothed are compatible with both SP3 and Koshini versions
The SP3 character/texture shown in the promotional renders is Elle by Syyd Raven (RDNA)
The Koshini character/texture shown in the promotional renders is Lady Winnifred by Sarsa (Faerie-Dreams) and the hair is from Koshini's pack 15
Other Credits: Iris from TransPond's bulb pack (RDNA), Hat from Digital Meanerings (RDNA 13 Days of Christmas 2004), Wonder Vase and Frame Shoppe by Ooh Betty (Renderosity).