I know this might not be the perfect place to find the answer I seek, but I work for Lumber Liquidators and I love This Old House. My mother recently purchased a mattress for my daughter. It seems pretty old, not necessarily antique, but has L channel rails. After measuring the L x W I came up with 66" x 52". After researching mattresses, I came up with zilch. Any Idea where I should start? I need both the mattress and box spring. My mother has sanded and painted the mattress I don't want to disappoint her.