Slow but productive evening this evening. Riveted and bolted the outboard seat ribs to the rear spar bulkhead/carry-through. Then riveted the outboard seat ribs to the floor panels. Next I installed nutplates onto the arm rests and bulkheads as required and then riveted the arm rest assemblies together. I clecod the assemblies onto the existing fuselage structure for the photo and to 'store' them until tomorrow. They will get back-riveted to the side skins and then the whole skin/arm rest assembly will be installed onto the fuselage mid-section (at some point).