IWC Ingenieur SL Automatic Ref 3506 Grey "Graph Paper Dial" leather-straps The no-lug-holes case remains in

The no-lug-holes case remains in outstanding condition as is the fluted yellow gold bezel

- Omega Calatrava 2325

The watch is housed in a waterproof 36mm case with cylindrical pushers and large size winding crown

The dial is another standout element

This watch houses a non-soleil silver dial in lovely condition with applied gold markers and hands

IWC Ingenieur SL Automatic Ref 3506 Grey "Graph Paper Dial" leather-straps The no-lug-holes case remains inIn the mid 1970s, IWC decided to redesign the Ingenieur to give it a more "fashion forward" look. With this new model, IWC aimed to emulate the success of one of its rivals. A few years earlier, Audemars Piguet had struck gold with the luxury steel sports watch, the "Royal Oak," designed by Grald Genta. In response, IWC brought Genta on board (who also designed the steel Patek Philippe Nautilus) to redesign the Ingenieur, along with two other models: