Hi Choice Vannys
They were sold as being in very good condition but in reality the white leather was in pretty rough shape. A politely but firmly worded complaint about the misleading description resulted in a partial refund. And a rummage through the crafts area resulted in a solution - shoe dye!
I wrapped the toes in foil to isolate the strap and was ready to go.
A few days and many thin coats of dye later and viola! Not quite like new but much improved.