De L'Isle MSS. deposited by the Rt Hon. the Viscount De L'Isle, V.C., September 1969 [in the] Kent Archives Office
SidneyFamily.
Kent Archives Office.
[Maidstone] Kent Archives Office,
[1974]
'Since this catalogue was compiled a further large deposit of papers has been received concerning the Foulis family of Inglesby Greenhow in N. Yorkshire ... The whole De L'Isle MSS. will ... comprise U1475 being those Sidney papers formerly deposited with the H[istorical] M[anuscripts] C[ommission] ; U1500 those Sidney papers which were left at Penshurst Place ; U1886 the Foulis MSS., yet to be catalogued'
Sidney Family
Kent Archives Office.