Alright so for my rebuild I treated the vent lid: 1/ cut the inner and outer lips so it's 7 mm high; 2/ cut off the part of the seal that is under the hinge to make the vent lid sit flush with the scuttle top panel; 3/ ground the heads of the vent fixing screws and removed the washers so they don't fool the vent lid;  4/ ground the forward edge of the hinge by 1 mm to prevent the rear of the vent lid from fooling the scuttle top panel. Now it's good until it's back from