I have all Edexcel Maths GCSE Higher Linear Papers from 2006-2013.
You may be wondering why I have them from the last eight years, but the older maths papers are pretty much the same as the ones that come up these days, the only difference is the time is longer. In 2006-2007 papers, you have 2 hours, however from 2008 onwards, you get 1 hour and 45 minutes.
Still pretty helpful and useful.
For Science, presuming your doing AQA, I would recommend doing past papers from 2012 onwards, as they are pretty identical to the papers you might be doing.