Dear CH,
#50 (mono version is #82) and #164 are the best option for you. #50 could be used with national colors or without them, black/white and on different surfaces. The shadow under the curved shape could be dropped depending where it will be used. It's clean, modern and reflects what you guys do – you deal with steel sheets transformations. Moreover, it's stylize as A – the first letter of your company. Same thing with #164 – entry has connection with a Aztec theme and has a steel-sheet reference. They are abstract.