The Must de Cartier line, introduced in 1977, brought the maison's most recognizable design to a wider audience without softening any of it. The Tank LM is the larger of the two classic sizes, and it wears the 1917 architecture at its most legible. This example is distinguished by an ivory lacquer dial left entirely free of numerals and applied markers, a configuration far scarcer than the Roman-numeral dials that define the line.
The case is vermeil — a sterling silver body hallmarked ARGENT and 925 beside the French boar's head, finished in twenty microns of gold and stamped PLAQUE OR G 20M on the reverse. It measures 23.5mm across excluding the crown and 30mm from lug to lug, proportions that read as restrained rather than small. The brushed caseback and the blue cabochon set into the crown are the only ornament the design allows itself.
Warm ivory lacquer fills the aperture, softened by age into a cream that leans toward champagne under direct light. Only the must de Cartier signature beneath twelve and the interlocking double-C at six interrupt it, with SWISS set discreetly at the base. Blued steel sword hands cross an otherwise empty field, and with nothing to compete against them the proportions of the case do all the work.
At its heart beats the manually wound Caliber 78-1, Cartier's designation for the ETA 2512-1, running at 21,600 vibrations per hour on seventeen jewels with roughly forty-two hours of reserve. The movement has been fully serviced and returns healthy amplitude on the timing machine. The daily ritual of winding reinforces the connection between the wearer and the mechanism within.
Completing the watch is a greige leather strap, carefully matched to complement the vermeil case and preserve its classic aesthetic. Not original to the watch, it was chosen for this piece and closes on a pin buckle. It fits wrists up to 17cm, and the 17.5mm lug width leaves the strap simple to change.
Elegant, purposeful, and unmistakably vintage, this Must Tank shows how little the design needs in order to remain unmistakably a Cartier.
- wrist size in our picture is 17cm circumference -
Specifications
Specifications and condition
Brand
Cartier
Ref.
681006
Year
1976-1981
CONDITION
Fully serviced 2026/09/07
Timegrapher +70.3s/d 292° 0.13ms
good overall condition, showing traces of use
DIAL
ivory lacquer dial
blued steel sword hands
STRAP & BUCKLE
greige leather strap fitting up to 17cm (not original to the watch)
17.5mm lug width
pin buckle
CASE
vermeil - sterling silver with 20 micron gold plating (ARGENT / 925 / PLAQUE OR G 20M)
23.5mm(excluding crown) / 30mm(lug to lug)
MOVEMENT
Cal.78-1 manual winding, 17 jewels, 21,600 vph
BOX & PAPERS
"PRINCIPE PRIVÉ" certificate of authenticity documentation card
