1) This unusual term is entered in the OED under the headword ‘arsedine’. It was a gold-coloured alloy of copper and zinc, rolled into very thin leaf and used to ornament cutlery wares.
Joseph Hunter’s Hallamshire Glossary defines it as ‘brass beaten or rolled very thin, used in the cutlery manufacture of Hallamshire to heighten, by its brilliant gold-colour, the beauty of the transparent horn sometimes used in the handles of knives’. Although it is little known elsewhere, assidue is recorded in several Sheffield inventories, including those of George Harrison: 1690 assidue 2˝ pounds, 8. 6., and John Towle: Assidue Twenty Eight pound weight, Ł5.