LID for storage box (Kendal LA9)

I would really like to have a lid (temporary use if need be) while I restore my outside storage box that needs the rotten lid replaced. Wood lid surround is intact. Dimensions are 165 cms x 69 (5ft 5" x 2ft 4" approx)
Anything waterproof or could cut down to size would be good if anyone could help. Thanks Eileen