I was looking for instructions too but amazingly I've just turned up the original paper ones in my filing system. For a "Cadiz" futon, looks pretty much like this
http://www.argos.co.uk/static/Product/partNumber/6276209/c_1/1%7Ccategory_root%7CHome+and+furniture%7C12107022/c_2/2%7Ccat_12107022%7CSofabeds+and+futons%7C12107178/c_3/3%7Ccat_12107178%7CMetal+futons%7C12107187.htm (currently called Mexico futon). If you want a scanned copy you'll need to let me have an email addy. Kath_online "at" thestennetts.co.uk
Kath, June 2009