Metal Frame Sofa that lies down in a Double Bed and Mattress (Richmond TW10)

Metal Frame Sofa that lies down in a Double Bed, 190cm x 135cm, and same size flat mattress. Comes with a mattress topper. It used to be a Futon, but the proper Futon mattress got replaced by the flat mattress. In oder to use it as a Sofa one would want to maybe use two separate, single mattresses