Installed the rivnuts on the vertical stabilizer parts. I used some high strength “red” lock tight on them (as suggested by Craig). Pretty easy to install these.
Also started to work on mounting the VOR antenna on RIB #4. I wasn’t supplied the mounting plate so I ordered some .81mm 6061 aluminum to make the plate. Will have to wait to work on that when the material arrives. It looks like the rivets are going to be a bit tough to get in near the antenna base. They will definitely need to be cut, but how much can they be cut? The VOR antenna is a RAMI AV-520 V STYLE VOR/LOC/GS ANTENNA I ordered from Aircraft Spruce (https://www.aircraftspruce.com/catalog/avpages/ramiav520.php).