1) The implement's precise function is not apparent in such contexts but it may have been a section of a tree trunk over which a hide could be draped when it was being ‘wrought’, similar to the beam used when the hide was converted into a butt or the scudding-beam in more modern tanneries.
I find no examples of this term in the standard reference works but it occurs several times in documents linked to Yorkshire tanners. In 1658, for example, the final items in the inventory of Richard Wadye of Selby were The working tree, apron, knife, bill, wood with other huslement : in 1660 John Titlow, also of Selby, had his working tree with the rest of his working tooles valued at 6s. In 1686, Samuel Cutler had In the tan house … 1 working tree and working knife, 1 choping bill, Selby.