| Historical records |
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| 1867 | Directory entry | Wallis William, esq., Oaklea | | Oaklea | Post Office Directory |
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| 1867 | Directory entry | Wallis William, surgeon, Oaklea | | Oaklea | Post Office Directory |
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| 1874 | Directory entry | Wallis William, Oaklea | | Oaklea | Post Office Directory |
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| 1874 | Directory entry | Wallis William, surgeon, Oaklea | | Oaklea | Post Office Directory |
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| c 1875 |  | Part of the 6 inch to 1 mile map of Sussex produced in 1875 by Ordnance Survey | | Oaklea | |
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| 3rd Apr 1881 | Census | William Wallis, M, Head, married, age 67, born Hartfield; occupation General Practioner | Dr William Wallis | Oaklea House | 1881 Census Hartfield, Sussex |
| 3rd Apr 1881 | Census | Louisa Wallis, F, Wife, married, age 59, born Surrey | Louisa Wallis [Evershed] | | |
| 3rd Apr 1881 | Census | Ellen L. Wallis, F, Daughter, single, age 32, born Hartfield | Ellen Louisa Wallis | | |
| 3rd Apr 1881 | Census | Katherine Wallis, F, Daughter, single, age 27, born Hartfield | Katherine Wallis | | |
| 3rd Apr 1881 | Census | Charles Wallis, M, Brother, single, age 64, born Hartfield; occupation Retired Veterinary Surgeon | Charles Wallis | | |
| 3rd Apr 1881 | Census | John Evershed, M, Father-in-law, married, age 86, born Surrey, handicap: blind; occupation Retired Farmer | John Evershed | | |
| 3rd Apr 1881 | Census | Louisa Evershed, F, Mother-in-law, married, age 83, born Surrey | Louisa Evershed | | |
| 3rd Apr 1881 | Census | Harriet Morphew, F, Servant, single, age 37, born Hartfield; occupation Cook | Harriet Morphew | | |
| 3rd Apr 1881 | Census | Sarah Napper, F, Servant, single, age 26, born Petworth; occupation Housemaid | Sarah Napper | | |
| 3rd Apr 1881 | Census | Alice Napper, F, Servant, single, age 16, born Petworth; occupation Housemaid | Alice Napper | | |
| 3rd Apr 1881 | Census | Daniel Vinall, M, Servant, single, age 22, born Withyham; occupation Groom | Daniel Vinall | | |
| 3rd Apr 1881 | Census | Murdoch MC Kenzie, M, Medical Assistant, single, age 37, born Scotland; occupation Medical Student | Murdoch MacKenzie | | |
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| 1882 | Directory entry | Wallis William, Oaklea | | Oaklea | Kelly's Directory |
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| 5th Apr 1891 | Census | William Wallis, M, Head, married, age 77, born Hartfield, Sussex; occupation: Retired General Practitioner | William Wallis | Oak Lea | 1891 Census Hartfield, Sussex |
| 5th Apr 1891 | Census | Louisa Wallis, F, Wife, married, age 67, born Albury, Surrey | Louisa Wallis | | |
| 5th Apr 1891 | Census | Katherine Wallis, F, Daughter, single, age 37, born Hartfield, Sussex | Katherine Wallis | | |
| 5th Apr 1891 | Census | Charles Wallis, M, Brother, single, age 74, born Hartfield, Sussex; occupation: Retired Veterinary Surgeon | Charles Wallis | | |
| 5th Apr 1891 | Census | Edith B Watson, F, Visitor, single, age 39, born Wandsworth, Surrey | Edith B Watson | | |
| 5th Apr 1891 | Census | Mary A Ball, F, Servant, single, age 50, born Pontypool, Monmouth, Wales; occupation: Professional nurse | Mary A Ball | | |
| 5th Apr 1891 | Census | Jane Edwards, F, Servant, single, age 20, born Hartfield, Sussex; occupation: Cook | Jane Edwards | | |
| 5th Apr 1891 | Census | Mary Baker, F, Servant, single, age 19, born Hartfield, Sussex; occupation: Housemaid | Mary Baker | | |
| 5th Apr 1891 | Census | Emily Twiner, F, Servant, single, age 15, born Edenbridge, Kent; occupation: Housemaid | Emily Twiner | | |
| 5th Apr 1891 | Census | Maurice Koettlitz, M, Boarder, single, age 31, born Belgium; occupation: Registered General Practitioner | Maurice Koettlitz | | |