Oh dear - bad news now...
A lot of time and trouble has been taken to hide corrosion instead of cutting it out and fitting fresh metal. New front outer seals have been welded over rotten inner sills. The lower box section of the chassis at the rear had been covered with filler and undersealed then painted to match the factory finish, this now means the rear axle and suspension will have to come out and new floor/box sections welded in. This only came to light as the panel beater was starting to take the paint back to the metal, to repair the lower wheel arch.
When the grinder was used to find fresh metal to weld the repair section in, what looked like factory stone chip paint had hidden what was a very big bodge. The trouble is BMW on this model fitted a black overseal which carried the lower chrome rails.