The Bate Collection A great collection of (mostly) playing instruments. Go visit!
Jacks etc Adam Swainson’s parts list, jacks & registers, keyboard pivot and guide pins and bushes. The best!
Music wire Malcolm Rose’s website; get your wire here!
Wound strings Lucy Coad, who can make your open wound strings brilliantly.
The British Harpsichord Society Web-based, growing source of information