Maybe it's that you want to stop after "found"? Leave it as: Alan Turing's notes found.

Yes, that's it you've found it. It's an interesting effect: "Alan Turing's notes found...being used as roof insulation at Bletchley Park". It's a very unexpected continuation of the sentence. (If you know the end you'd expect it to be written "Alan Turing's notes being used in roof insulation at Bletchley park" if that's the main point.) Thanks.

As far as UK headlines go, this is one of the more readable ones. There's a trend of compressing them to the point that they sometimes become ambiguous with humourous alternative meanings; something like:

"Alan Turing notes roof insulation"

The "found" adds a suggestion of surprise. "X's y being used as insulation" makes it seem commonplace or unremarkable and also suggests a continuation of the use. "X's y found ..." makes it clear it was a surprise and also suggests that the notes were removed.

/Native en-GB speaker.

To me the title sounds like they just took some of Turing's known notes and stuffed them into the roof not that they've just discovered more notes.