All walls have been insulated, taped and checked to assure proper blocking (in this case 1/4" piece of plywood) is provided for any wall-mounted fixtures such as behind the stove, behind the upper half of the shower, where the table bracket will be, etc... All wires are concealed/protected. Skins have been hung for the two sidewalls including windows/vents on the street side.
One change I've made is how the skins attach to the underside of the trailer. The metal originally wraps to the underbelly and is screwed sideways into the wall framing along the very bottom of the trailer; this only depended on contact between the metal floor pan and the skin for water-proofing. I've instead added putty tape (the same tape that's used around all doors and windows) to seal this connection and prevent kicked up water from wicking into the wall framing.
Original aluminum windows were heavily oxidized and rusted around the screws. A tutorial on how to disassemble and clean jalousie windows was recently uploaded here which is the general process I followed. I removed all glass panes and weather stripping before washing the frames with phosphoric acid. Final cleaning achieved with metal polish and fine steel wool.
A few panes were falling lose and one window was duct taped to hold them together. I discovered this is caused by dried-out rubber discs that hold them in place; I ordered a bunch of new retainer discs from Vintage Trailer Supply and this fixed the problem. I also ordered a roll of vinyl glass seal to minimize drafting. The street side windows are installed and overall I'm happy with them.