IWC INGENIEUR REF 3506 STEEL International Watch Co., Schaffhausen, " Ingenieur Automatic'', case No. 2388290, Ref. 3506. Made circa 1988. Fine and very rare, tonneau-shaped, center-seconds, self- winding, water-resistant, antimagnetic, stainless steel ...
IWC Ingenieur with box and some papers IW 3521 for $8,858 for sale from a Trusted Seller on Chrono24
1986 IWC Ingenieur SL 3506 Box and Papers | Facebook
HODINKEE reviews the vintage ref. 3521 Ingenieur SL from IWC