Today I was able to install the replacement rib 6. I opened all required holes to match the 4mm holes in the new rib & as I have re-used other parts that had been riveted with 3.2mm hardware, I opened those holes up so that the entire assembly is now held together with the larger rivets. That necessitated shortening some rivets to allow the required clearance. I primed the mating surfaces of all the rib 6 parts & the replacement upper ribs 1 through 5.