Well....they were almost a casualty of the quartz crisis and were swallowed into a consortium SIHM...later Swatch.
They essentially reached a post moon-watch peak where they were introducing landmark 44-47mm case designs like the Seamster PloProf 600M, Seamaster 1000m Cousteau Diver and Flightmaster Pilot that were taking on the Rolex Sea Dweller, GMT, and Daytona at similar price points. Unfortunatley, many of these never sold (like Daytonas too); they were left in jewellers vaults and in some cases 30 yrs later were still NOS, with purple wax seal on caseback in original boxes. I purchased dozens of NOS models from this and many other brands in 2000, when ebay first swept germany/swiss, and heirs were liquidating estates.
These late 1960s early 1970s models are the holy grail Professional watches that now fetch $5000-25,000.
Unfortunately there was the early 70s oil price shocks, massive inflation, currency devaluations, gold spikes and numerous anti-luxury consumer sentiment that saw everything from Gucci to Lamborghini facing collapse.
They cutback their model line, expanded to ANY jeweller willing to put up a cardboard counter sign and gave up on pricing discipline. In late 70s you could find Omegas being sold next to Seikos in same case, with quartz slapped on dials.
Then in early 80s you slowly started to see them listed on the famed Wall St. Journal Tourneau Corner 2nd page ad. They revived the moon-watch legacy and stated 'manual wind' which was an anachronism. Then they re-asserted control over authorized dealers and stopped discounting and aggressively pursued branding and celebrity sponsorship from Schumacher to Bond to Supermodels & Rockers). During the 90s bull-market it was the first watch every jr. exec got after their TAG-Heuer, and before a Rolex (VP bonus buy!). Then by early 2000s it had regained its true aura as the legacy of the Moonwatch was harnessed (Apollo 13), and the massive model range (Planet Ocean, Seamaster, Co-Axial, Ladies Constellation) was producing billions in sales, leaving the small in-house calibre brands in its wake.
Its a great history, but IMHO only the Moonwatch has iconic legacy; like Rolex Gold President, Audemars Piguet Royal Oak, or Patek Philipe which introduced landmark designs in dress, sport, or complication watches.