I might not be the first to point this out, but Parliament now has Hansard available online from, it seems, 1950 onwards. As ever, TheyWorkForYou.com provides a much-improved search engine. The first searchable Winston Churchill speech is him welcoming the Speaker to the chair in 1950 after the General Election of that year.
Margaret Thatcher was first elected in 1959, and I knew she had introduced a private member's bill to make Local Council meetings open to the public. What I didn't know was that her maiden speech was the one introducing the Bill! This is really remarkable - both events are quite nerve-inducing, the maiden speech and introducing a private member's bill, but to do both at once is really quite something! Characteristically, she wastes little time with the conventions of the House, where maiden speeches are traidtionally uncontroversial, praise one's predecessor and talk about the constituency. Here is how her speech starts:
Mrs Margaret Thatcher (Finchley)
I beg to move, That the Bill be now read a Second time.
This is a maiden speech, but I know that the constituency of Finchley which I have the honour to represent would not wish me to do other than come straight to the point and address myself to the matter before the House.
and then she is straight into the Bill!