Hand over to bro, again:
"Thanks, Hoagie.
Celestia was a labour of love! I used the pink talking toy as a base (the white hasn't made it over here in the UK, but I suppose that's moot). The hardest part was the reassembly. All the gimmicks and things were removed, and the toy simply doesn't fit back together without them (getting it apart was tough enough!). The saddle, neck, chest and head are totally remoulded (that blasted hair and horn! Argh!), as are the wings.
The new hair was a nightmare (um, arf?). Days and days of trial and error, to get that strange ethereal look. I hope I succeeded.
I remade the electronic circuit, giving it new colour LEDs, a battery box, a new sturdy switch and I upped the voltage a little. That's all tucked away in the base (a cobbled-together mess of wood and plastic).
Overall, I'm happy with how the build went, and I'm positively in love with her now!

In truth, the work requires little skill or technique. Anybody can do it! Some good filler, sandpaper, paint and glue is all you need. Feel free to ask how I did specific things - I'm more than happy to share."