Normally they're done the other way around - Grade 5 theory just before grade 6 practical. Some of the pieces will be out of copyright - you can download them from IMSLP.
Do exam boards like ABRSM and Trinity let you use downloaded copies, even if it may be out of copyright? I thought it's their policy to ban photocopies.
Exam boards are fine with it so long as they are out of copyright.
Then in theory anyone could use downloaded music before 20th century. Are the examiners really going to spend time analysing whether a particular edition which has been scanned and uploaded to the Internet is out of copyright?