I wrote to Longines via their website. They can provide information on the year of manufacture based on the movement's serial number. It's a free service they offer.
It’s that day again - back on the slightly more subdued NATO today. I wish I could find a better quality strap in this color combination, with black PVD hardware; I saw one online a few weeks ago, but do you think I can find it again now...? 🙁