Cardboard pill box containing parts for a standard English detached lever escapement, including a complete but un-cut compensation balance. Partly finished and ready to be fitted, the box marked for its intended watch, No 9890, and bearing its makers name. Box 23 mm diameter.
Not sure of the name on the box lid, Costin being an escapement maker with which I am familiar.
The work of one of the twenty or so rough watch movement specialists, in box as supplied. A rare survival, the steel work in fine condition.