have a look behind the sofa in case you have a 12 Volt, 1.8 degree stepper motor lying around thaqt you donlt need - will be intersted - pay £ 5 for working one. Needs to be small, 40 mm diameter or less.

Old printers are a cracking place to start looking. Get yourself down to your local recycling centre. Most have a section for old electronic equipment, and if there aren't any printers in there, I'll eat my hat (and it is one of them russian Muskrat fur hats, although not real fur...)

Cheers
Andy

And if you are contemplating DIY throttle bodies, they are a good source of butterfly shafts.