Wristwatch · Grande complication wristwatch

IWC Grande Complication Ref. 3770

Partially verified

This IWC Grande Complication wristwatch, reference 3770, is a limited edition piece from a run of 50, identified as number 44. Produced circa 1991, the watch is encased in platinum with a diameter of 42.3 mm and features a screwed case-back secured by six screws. The timepiece utilizes the self-winding Caliber 79091 movement, which incorporates over 659 individual parts to power ten horological complications, including a minute-repeater, an 1/8 second chronograph with 30-minute and 12-hour recorders, and a secular perpetual calendar. The white dial displays the day, month, moon phases, and a millesimal year indicator. It is fitted with a black crocodile leather IWC strap and a platinum buckle. The watch is presented as part of a set including the original fitted box, certificate of origin, and an instruction booklet. The auction description reports the watch was sold on July 17, 1992.

Front view of the IWC Grande Complication Ref. 3770, showing the white dial with perpetual calendar indicators and chronograph registers. — Antiquorum. Rights pending — permission not yet requested. Original source

Catalogue identity

Source: catalog.antiquorum.swiss
Category: Wristwatch · Grande complication wristwatch
Maker / attribution: International Watch Co.
Reference: 3770
Catalogue / lot identifier: 261
Source-reported date: circa 1991
Source-reported place: Switzerland
Source-reported serial: 2 552 044

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial Construction

The timepiece features a large, round-shaped platinum case measuring 42.3 mm in diameter. The construction utilizes an inclined bezel and a case-back secured by six screws. The watch includes a screwed-in winding crown and a minute-repeater slide mounted at the 9 o'clock position on the case flank.

The white dial contains subsidiary dials for the 30-minute and 12-hour chronograph recorders at the 12 o'clock and 6 o'clock positions respectively. Subsidiary seconds are located at 9 o'clock. The dial displays the date of the month at 3 o'clock, with day and month indicators presented in German. An aperture for the moon phases is located at 12 o'clock, while a secular millesimal year indicator is visible through an aperture positioned at 7:30.

Evidence for this section

“Platinum, self-winding, round-shaped, large gentleman’s wristwatch, case-back screwed by six screws, screwed winding-crown, inclined bezel”
“Minute-repeater on two steel gongs (activated by the slide at 9 o’clock)”
“Millesimal of the year (aperture at 7:30; century, decade and year)”

Movement and Complications

The watch is powered by the self-winding Caliber 79091. The mechanism comprises over 659 individual parts, designed to provide a high level of complexity in a user-friendly format suitable for daily wear. The complications include an 1/8 second chronograph, which is managed via two rectangular push-pieces, and a chiming minute-repeater that acts upon two steel gongs.

The perpetual calendar is designed as a half-instantaneous system, calibrated to cover a period of 500 years. The automation of the movement is intended to support the functionality of the calendar and chronograph alongside the timekeeping functions.

Evidence for this section

“With over 659 individual parts, the watch houses an impressive number of complications: perpetual calendar calibrated for 500 years”
“Nevertheless, Klaus wanted to keep the watch more “user-friendly” by choosing an automatic winding method fit for daily use.”

Provenance and Documentation

This example is one of a limited series of 50 pieces, specifically identified as number 44. The watch is accompanied by an original fitted box, an outer box, and a certificate of origin. Additionally, the set includes an instruction booklet and a book written by Manfred Fritz titled “Grande Complication.”

The auction house notes that the watch received servicing, with the associated service paper dated 2019. According to the provided documentation, the watch was originally sold on July 17, 1992.

Evidence for this section

“Limited Edition 44 / 50”
“Accessories original fitted box and outer box, certificate of origin, instruction booklet, the book by Fritz, Manfred”
“The certificate mentioned that this watch was sold on July 17, 1992.”

Open research questions

What specific technical modifications were made to the base Caliber 79091 to facilitate the inclusion of the secular calendar module?
How does the specific sequence of production for the 50-piece series align with the 1990 presentation date versus the 1992 sale date?

Source evidence

Recorded claims and source quotations for IWC Grande Complication Ref. 3770
Field	Source-reported value	Source quotation
Material	platinum	“platinum”
Reference	3770	“Ref. 3770”
Caliber	79091	“Caliber 79091”
Limited Edition	44 / 50	“Limited Edition 44 / 50”
Case diameter	42.3 mm	“Diameter 42.3 mm.”
Movement type	Self-winding	“self-winding”
Sold date	July 17, 1992	“The certificate mentioned that this watch was sold on July 17, 1992.”

Visible details

German language day and month indicators
Minute-repeater slide located at 9 o'clock
Millenial year aperture positioned at 7:30
Case-back engraved with series information and serial number

Research qualifications

The auction house reports the watch was invoiced for service in 2019
Source notes the perpetual calendar is calibrated for 500 years

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

IWC - Ref. 3770, large, self-winding, minute-repeater, chronograph, minute and hour recorders, secular millesimal perpetual calendar, moon; limited edition of 50 pieces; platinum

Reviewed 2026-10-26 · Record 788f2a04ae

Terms in this record

Glossary explanations for terms named in this object’s record.