Round day-date Constellation (integrated bracelet)
What it is
Omega Constellation chronometer, day-date
Case ref is almost certainly 168.0054 with integrated bracelet ref 368.851
Movement: automatic cal. 1021 chronometer (day-date) - standard for this reference
Period: around 1970–1973
Material: all 18k yellow gold - case + bracelet, and very likely gold dial (“OM SWISS MADE” at 6 o’clock usually indicates a solid gold dial)
Your bracelet clasp is stamped 368.851 and Swiss hallmarks
Published weight / gold content
Total weight: ~153 g complete watch (case + bracelet, full length)
Approx 18k gold alloy weight ≈ 153 g − 18 g = 135 g
Pure gold content (18k = 75%) ≈ 135 × 0.75 ≈ 101 g
“Melt” value ≈ about €11,900
Your example
Your watch shows honest wear: surface scratches, aged dial, unknown service history, but appears original and on its full-length bracelet. Taking all that into account and current very high gold prices:
Private sale to an enthusiast (no recent service, but running): roughly ≈ €9.5–13k
Dealer retail asking price: think ≈ €12–15.5k depending on how nicely it presents after a light polish and service.
If this is the one with box & card and everything is matching, you can justify being towards the upper end of those bands, maybe +10–20%.
Rectangular “TV” Constellation - ref BA 351.013
What it is
Omega Constellation automatic, two-hand (no seconds), rectangular / TV-shaped case, integrated bracelet.
Your clasp stamp 351.013 plus “750” in a lozenge and Swiss hallmarks = reference BA 351.013 in solid 18k gold (BA = yellow gold in Omega speak).
Movement: documented as cal. 711, an ultra-thin automatic (micro-rotor / full-rotor) used in slim dress Constellations of the 1970s.
Period: around 1973–1975
Material: case, integrated bracelet and clasp all 18k yellow gold (750) - confirmed by the stamps you see and by dealer descriptions.
Weight / gold content
There’s no published weight for BA 351.013, but we do have for its very close cousin:
Constellation “TV” BA 368.0847 (also 18k with integrated bracelet) is documented at 143 g total weight on several dealer listings.
Your 351.013 has:
Similar style of wide, heavy bracelet. Slightly different case shape and simpler 2-hand dial (cal. 711 instead of 1001), so the head might be a bit lighter. A reasonable, honest range for total weight is ~130–145 g. Using the same “subtract ~18 g for non-gold parts” rule:
Pure gold value ≈ €9,800–11,100)
Your example
Condition looks decent but not mint: case and bracelet show wear, service unknown.
Given that and the current gold price:
Scrap / gold buyer: roughly €7.7–9.5k (depending on actual weight).
Private sale to a collector: something in the €8.5–12k band feels realistic.
Dealer retail asking price: likely ≈ €11–14.5k for a freshly serviced, nicely detailed example.
If this is the watch with original box & purchase card and they match the serial, aim towards the high side of that range.
Are they both solid gold?
Short answer: yes.
The “750” mark on the second clasp explicitly means 18k gold.
The 368.851 bracelet is documented by Omega and multiple auction houses as an 18k yellow-gold integrated bracelet.
“BA” in Omega reference numbers means solid yellow gold, not plated or capped.
So both are “serious” precious-metal pieces, not just gold-capped.
How I’d think about them overall
At today’s crazy gold prices, the melt value alone is already five figures for each watch.
As watches, because they’re niche 70s integrated designs rather than classic 50s pie-pans, they’re less liquid but definitely collectable to the right audience.
