Watch List notes:

WORLD COINS, FRANCE, Charles X, Silver ¼-Franc (2), 1828-T, 1829-T, Nantes, head left, rev crowned arms (Gad 353; KM 722.11). Both mint state with some original lustre under an attractive cabinet tone, very rare in such high grade. (2)
mintage of 6316 and 6481 pieces only respectively

Estimate: £200-250