This deserves an update.
I have delved into the subject since, and have found ( 'with a little help from my friends' ) these lugs are indeed correct. In some gold capped watches, not limited to Eterna, the topside and only the topside was gold capped, meaning the cap isn't supposed to reach around the bend. Given the condition of the watch and the intricacy of the chamfers, logic dictated this to me from the get-go, but this was literally the first watch I had found to feature this finishing. Therefore I felt it
couldn't be right. It now turns out
I wasn't right.
I'll post some pics I snapped today, to make up for the long read. Initially, given my fear for the ruined lugs, I was unhappy with this acquisition. Knowing what I do now, however, I'd rate this watch in excellent condition and I am very pleased to wear it.