Yabba Dabba Do, you are looking at some welding on the floors (and probably the trunk). Also, check out the taped in windshield on the lede photo. More rust. The ad also notes that in addition to the usual rust spots, there are some unusual spots caused by rodent nests (oh boy, Hantavirus). If you aren't familiar with 70's FIAT rust, the story goes that in exchange for helping AutoVaz set up the Lada factory and licencing the 124 to the Russians as the VAZ-2101, payment was partially made in Russian steel, which contained a high carbon content, leading to the rust problems of the 70's.
Gianni is Daily Turismo's Pacific Northwest correspondent. He's in agreement with PhiLOL on the subject of rust.