Watch movement by Thomas Tompion with a later case and dial

Watch movement, with later dial and pair case, by Thomas Tompion, London c.1680. The outer case is covered in tortoiseshell inlaid with silver in a pattern of birds and flowers, the inner case is plain silver. The white enamel dial has steel beetle and poker hands. The movement has a verge escapement, four wheels in its train, and an unusal shaped balance cock. The balance-spring has 4 turns and is therefore probably not the original spring. The movement is signed 'Tho Tompion London' but is not numbered and therefore made prior to about 1680.

Clockmakers' Museum No. 48