sending evidence?

Hello, when sending evidence. ie from the hospital.. consultant or specialist nurse etc, does it have to be the original letter or can you just send photocopies of everything? some of the evidence i have though has already been photocopied by the hospital and then sent to me.

Also is it ok to include evidence from several years ago and to back it up with current evidence? i won an appeal over ten years ago, do i mention this and submit some paperwork/evidence from that or will that be seen arrogant?! that i think i'll automatically get it. im currently going from dla to pip. thank you