What I would do is take the 3.75 yards = 135 inches, iron it completely open. Then I would fold it in half lengthwise (so it's 67.5" x 40 x 2 pieces). Now, without cutting, I would sew the lengthwise piece. Cut off the fold off. Open it up, you now have a piece 67.5 x 80. Quilt back, 2 pieces, no cutting. Position it appropriately
For you more visual people: Put your hands out, both palms facing you, with your fingertips touching (middle to middle, pointer to pointer, etc). Fold your hands together, so they are exactly on top of each other. Now fold them open along the pinky "seam". Nice big rectangle of hands from a long skinny one
:mrgreen: :mrgreen: