It is nice, but not absolutely necessary, to drill and rivet the alum strip to the rib before you put on the final finish tape. This hides the rivet heads nicely.

Also, after you get all the fabric and paint on the rib, the wingtip joint will be more uneven than it is now. One way to fix this is to put a shim strip of something (I used some of the windshield self adhesive thin foam) on the aluminum strip before you slip on the wingtip.

Jim