I'm not sure there is a "correct" term. All I can say is it looks to me more like a curtain than a ribbon...
This is my Constellation, which I inherited in 2014. When I got it I put it in for a rather expensive service and it came back with a different style crown. It did have a hexagonal or maybe decagonal crown, which I preferred but it’s not the end of the world. I don’t know the model reference ( please help) but I know from the Omega service card that the calibre is 551. It was originally purchased in Paris in 1962, so I guess it was made a year or two before. Putting aside the emotional attachment to a piece you have inherited, I love it and wear it most days. I get loads of comments about wearing a vintage watch and I have to admit that I get such a kick out of owning something that is now 55 years old and keeps more or less perfect timing. The levels of craftsmanship deployed back in the early 1960's must have been off the scales and I just hope my modern Omega ends up being half as good over the long term.
Newly acquired and purchased locally from the original owner. SN dates the watch to 1968/9. Reference 168.010/11. Solid 18k case, bracelet (aftermarket) and dial. Would be interested in a period correct Omega box (with a holder/cushion) if anyone has one lying around.
This is my Vintage Omega Constellation from 1969 and with Cal. 751 model 168.029 SS with 18K gold bezel all original.