All our pre-owned watches come with a two-year warranty from Manfredi Jewels. Our Finest Pre-Owned & Vintage Watches. Since 1988, Manfredi Jewels has been in the watch and jewelry business trading a wide range of vintage/ pre-owned watches and fine jewelry from the most prestigious brands. The knowledgeable staff includes several on-site watchmakers who are expert in the rich historical background of horology providing insights on every single piece as well as checking originality and functionality. For this reason, Manfredi Jewels provides 24 months of warranty for each watch sold.Each watch is selected by a pool of passionate watch enthusiasts led by Manfredi’s owner and lifelong watch collector Roberto Chiappelloni.