What a cool and unique time piece! This is a vintage Girard-Perregaux skeleton pocket watch. This watch is working well and keeping good time. Pics: https://imgur.com/a/zKSoiAE Timestamp: https://imgur.com/a/UzX7V9J 43mm case with exhibition back. 12-hour dial with Roman numerals. Sub seconds. Standard push/pull crown for time setting. I believe these watches were made special for Shell Oil, which is why it says "Shell" on the mainspring barrel. I'm not sure when it was made, but if I had to guess, probably 1960's or 70's. A very cool a unique looking movement with a very angular design. Obviously made in-house by Girard-Perregaux. What a cool pocket watch design! Asking $195 USD OBO including shipping within North America. Great international rates available too.