| Andrew George Wilson | Director | 1 Jan 1999 | 29 Dec 2015 | British | 75 years |
| Catherine Grant | Director | 30 Oct 1995 | 20 Dec 2000 | British | 96 years |
| Chris Andrew Hamilton | Director | 14 Jul 2014 | 29 Apr 2022 | British | 57 years |
| Gordon Hoyle | Director | 28 Jun 1991 | 30 Oct 1995 | British | 100 years |
| Haydn Philip Wilson Payne | Director | 21 Jan 2022 | 27 Feb 2025 | British | 62 years |
| Hubert Giblin | Director | 30 Oct 1995 | 6 Jul 2000 | Irish | 90 years |
| James Joseph Grant | Director | 30 Oct 1995 | 14 Mar 2011 | Irish | 68 years |
| John Brian Hoyle | Director | 28 Jun 1991 | 29 Jan 1999 | British | 76 years |
| John Gerard Wernicke Smart | Director | 28 Jun 1991 | 15 Sept 1994 | British | 80 years |
| John Gerard Wernicke Smart | Secretary | 28 Jun 1991 | 15 Sept 1993 | British | - |
| John William Davis | Director | 28 Jun 1991 | 30 Jun 1996 | British | 88 years |
| John William Davis | Secretary | 15 Sept 1993 | 30 Oct 1995 | British | - |
| Martin Grant | Director | 30 Oct 1995 | 21 Feb 2000 | Irish | 98 years |
| Michael Russell Meanley | Director | 8 Apr 2011 | 8 Jul 2014 | British | 59 years |
| Peter John Underhill | Director | 28 Jun 1991 | 30 Oct 1995 | British | 77 years |