1968 Longines Prototype Ultra-Chron Presented to The Observatory Contest in Neuchatel (N.O.S)

Manufacturer	Longines
Model	Prototype Ultra-Chron
Year of Manufacture	1968
Reference no.	8056-1
Product no.	B-10652
Price

Manufacturer

Longines

Model

Prototype Ultra-Chron

Year of Manufacture

1968

Reference no.

8056-1

Product no.

B-10652

Price

Manufactured in 1968, this Longines timepiece is an exceptionally rare, unused watch from the Neuchâtel Observatory Contest. A precious piece exhibited at the renowned Neuchâtel Observatory in Switzerland, it later served as a prototype for the Ultra-Chron series. The Cal.431 movement it houses was among the best with its high-frequency oscillation of 10 vibrations per second at that time. The watch was meticulously crafted to pursue precision and visibility, featuring a working dial reminiscent of instruments used exclusively in customer service during that era. This contest sample watch is highly valuable due to its extremely limited production, and its future market value is unpredictable given its rarity. The excellent preservation condition is as remarkable as its rarity. The unused item still retains a protective film on the case back and a sticker with the movement serial number. The dial has multiple variations, and this particular piece has a square index printed at the 6 o'clock position. The original strap and buckle are included.

Item details

Serial no.	15,234,***
Caliber	431
Movement no.	14,628,***
Movement type	Automatic
Material	Stainless steel
Case size	35mm
Case type	Screw back Water-resistant

Dial	Original
Type of Indices	Print
Belt	Original (18mm, lug width) / Original Buckle
Evaluation case	98％
Evaluation dial	97％
Evaluation mov	98％
Condition	5
Rarity	5

Other details

Case: There are some scuffs from storage, but the back of the case retains the protective film and the sticker with the machine's unique number.

Dial: Slightly aged, but very clean with no noticeable scratches or stains.

Movement: Never used. We will be happy to adjust it and deliver it to you upon request.