Finished riveting the top skin, did not rivet the hinge. Installed the plastic tips, the bench mounted belt sander does a good job getting the tips flat. To drill the holes through the tip to the rib I used the rivet spacer guide (I previously enlarged the holes in the guide to allow me to drill straight thru...big time saver).
Important Tip: When installing the plastic end caps, an easy way to keep the rib in the 90 degree position is to use a plastic square, drill a hole through the rib and the flange of the square and use a cleco to hold in position. A piece of duct taope works well on the other side of the square...when you're done you can leave the hole in the rib as is or do what I did and put a rivet in the hole.
