Definitely keep scanned copies, I would suggest scanning the originals at the highest resolution you can and keep two or three scans of each.
I've just remembered that the records office also suggested storing the documents (when in their individual wallets and tissue paper) in the dark and dry so that there can't be any further light or damp degradation of the documents. One of my documents, an early 1800s apprenticeship agreement, has a tea mug ring stain on the back which could cause further damage if it got even slightly damp; luckily it's on a very thick legal parchment.
