As a premier maker of gentlemen's wristwatches, the foundation of its line has ever been the simple hand-wind, typically with subsidiary seconds, and it is here where I think the saddest decline occurred. Since the 1930s at least, most Vacheron & Constantin wristwatch calibres were essentially more refined variants of movements used by Jaeger-LeCoultre for its own watches. The gap in quality grew over time, until the raw ebauches supplied to Vacheron & Constantin could be seen to have only a little in common with their Jaeger-LeCoultre counterparts, and with the finished movements being a world apart. Such a case were the calibres 1001 and 1002, which were provided exclusively to Vacheron & Constantin and Audemars Piguet.
Other high-grade calibres like the 1003, 1171, and 1120, had no in-house counterparts at Jaeger-LeCoultre, which served only as a supplier of the raw ebauches. An elegant calibre in five bridges, the sub-seconds 1001 and the center-seconds 1002 had formed the basis of Vacheron & Constantin's reputation in the 1950s and 60s. They were matched only by the peak 10 and 12 ligne handwinds of Patek Philippe, and I would not hesitate to classify the 1002/2 as one of the very finest indirect center-seconds handwinds ever produced. The contemporary counterparts to these movements used by Jaeger-LeCoultre and LeCoultre were the calibres 818 and 819. Sharing the same basic "footprint" as the 1001, the 818 was a simplified economy design never intended for use in fine watches.
It might be most appropriately compared to the present ETA calibre 7001, a solid and reliable extra-flat hand-wind used in inexpensive watches. The elegant curve and sweep of five bridges in the 1001 as largely destroyed by the crude joining of the center and third-wheel bridges in the 818. With the addition of a freesprung Gyromax balance in the 1001/1 and 1002/2, full Genevois finishing, adjustments, and the Geneva hallmark, there could really be no comparison. Alas it appears that in the late 1970s (or early '80s) that Vacheron Constantin either elected, or was forced to give up the 1001 and 1002, and take up the inferior 818 which it redubbed calibre 1014. This movement did not feature the option of a freesprung escapement, and it does not appear that Vacheron Constantin would often elect to brand it with the Geneva hallmark, if ever. It was of course finished to the high Genevois standard in all other regards. Calibre 1014 has formed the backbone of Vacheron Constantin's production of handwound wristwatches (as shown above) for nigh on a quarter-century, a movement which in recent years it has had to share with Chopard, Breguet, and perhaps others, though Jaeger-LeCoultre itself elected to stop using it several years ago. The shift from the 1001 to the 1014 is akin to the technical and aesthetic decline of Patek Philippe's 23-300 PM to their present 215 PS, if only steeper.