The lower two canvas door grommets on northern end tore through. Used two pieces of angle flashing, bent in half, drilling #40 holes for two rows of rivets. Held the flashing on the edge of the canvas while drilling #30 holes through canvas. Deburred front and back, cleco'd together and riveted with 1/8" Harbor Freight rivets.
Drilled 1/8" locating hole for lag screws, updrilled with step drill.