While Patek https://www.watchesx.co.uk/Collection/iwc/ leaned on valley https://www.replicauhrx.de/produkt-kategorie/iwc/ watchmakers into the 20th Century, some companies that made https://www.watchesx.co.uk/Collection/tag-heuer/ in-house movements occasionally fulfilled special orders with outside help. For Patek, it's possible that in this case they bought movements when a respected manufacturer closed. While there's no doubt that Patek Philippe did the finishing, it's possible the groundwork was laid some 50 years earlier by Meylan.