Mine is the small flap, not the medium. I bought mine in Harrods and they had beige, pink and the blue in iridescent in small and medium flaps and WOCs. I bought the bag on the 30th March but I was in Harrods again on Saturday 6th April to get the card holder and they had even more stock of iridescents. I can't recall the stock of black iridescents as I wasn't really looking for these. No mini's in iridescent but they did have minis in nude, the coral red/pink, green and coral red/pink with the gold studs/charms on it all on display. All were lambskin, all had antique gold hardware and they had square and rectangular for all of them. They also had minis in the pink tweed and green tweed. I asked about other minis they might have in the back but they only had those ones mentioned. I always go to the 3rd floor Womenswear department in Harrods, rather than accessories on the ground floor as it's a lot quieter, the SAs are really helpful and you don't feel rushed at all. I think I paid £3,810 for the small iridescent beige flap and £330 for the card holder.
Hope this helps. Let me know if you want to know any more Harrods stock. I only live round the corner and end up in there every weekend admiring everything!