Other than the part where the British changed it in 1994 and so the Chinese made their own one post-handover in 1998?
The 1994 changes were pretty substantial:
> When Chris Patten arrived, the Legislative Council (LegCo) was composed of only 18 directly elected seats from the Geographical Constituencies (GCs), 21 Functional Constituencies (FCs) mostly selected by the powerful elite groups in Hong Kong, 17 members appointed by the governor, 3 ex officio members (namely the chief secretary, attorney general, and financial secretary) and the governor himself as the President of the LegCo.
> The electoral method of the 1995 Legislative Council was fixed under the Basic Law, the mini constitution of Hong Kong after 1997, with only 20 directly elected seats from the geographical constituencies, 30 functional constituencies, and 10 seats elected by an election committee. To broaden the democratic structure of LegCo under such a framework, Patten had to find room under the Joint Declaration and the Basic Law.
> On 7 October 1992 during his inaugural policy address to the Legislative Council, Chris Patten announced his 1994-95 electoral arrangements. The proposal included:[3]
- "single seat, single constituency" measure should be applied in geographical constituency elections including the Legislative Council, Municipal Councils and District Boards;
-Lowering the minimum voting age from 21 to 18;
-Abolishing all appointed seats on the District Boards and Municipal Councils;
-Removing all the restrictions on local delegates to China's National People's Congress to stand for election;
-Broadening the franchise of certain existing functional constituencies by replacing corporate voting with individual voting;
-A total of 9 Contemporary functional constituency seats should be brought up so as to let about 2.7 million people have the right to vote; and
- Introducing an Election Committee of District Board members to return 10 members to the Legislative Council.
> In this way, Patten extended the definition of functional constituencies and thus virtually every Hong Kong subject was able to vote for the so-called indirectly elected members of the Legislative Council.
Even so, even if you say the current LegCo is descended from the pre-handover one, the pre-handover LegCo was one of the things that the British negotiated with China.