It's a very interesting question and I'm glad you've asked it, because I was the custodian of all previous prime ministers' papers. I used to deal with the previous prime ministers on a regular basis as requests for their documents came in. Each of those previous prime ministers had designated someone who would review the documents on their behalf, who was a privy councillor, sworn, etc.
The answer is clearly no. Those cabinet documents, the day of the election, become secret to the new government. That is the tradition in Westminster parliamentary democracy.