Restoration watchmaker Tobias Widmer expertly overhauls the calibre.

This Ingenieur SL “Jumbo” Ref. 1832 dates to about 1976, making it nearly 50 years old. A landmark design by Gérald Genta, it remains one of the most iconic and collectible Ingenieur models. Last serviced eight years ago, it arrived with pronounced scratches and deep dents – particularly on the case – requiring extensive restoration to return it to its original geometry. Restoration watchmaker Tobias Widmer expertly overhauls the calibre. He carefully inserts the balance wheel, oils the ruby setting, positions the date disc, and adjusts the rotor.