Thanks!
I tested both Peachy and Tutti Frutti for squeeziness after they had defrosted and they seemed to have no problems, other than this weird colour thing with TF's symbol, but that may have already been there (although i don't think so).
I'm a bit paranoid about freezing any nirvanas due to different plastic types, but if I do have to do any, I will make notes on the outcome. Hopefully I have caught everything now. It is getting like Fort Knox in my pony room.
I have only ever had trouble with 2 ponies actually having hair nibbled through, not the ones I froze, but Gypsy and Whirly, both of whom already had slightly faded hair, and were still dirty. Normally the moths eat the dirt off organic fibres, but incidentally bite through the actual fibres. The pony hair gummed them up and killed them, but the damage was done.