For me any great interior is a mix of old and new. These are my go-to resources for vintage finds (that also ship to Italy!).
1. Vinterior - A collection of inventory from antique dealers throughout Europe this is the place to find that vintage gem you always dreamed of!
2. Selency - This French website is a mix of preloved vintage and recent designs. Most sellers ship throughout Europe. It is a great place to see if you can't find a second hand version of a current piece you love but maybe stretches the budget a bit too much.
3. 1st Dibs - This website is for the collector. Their selection tends to be higher-end, more valuable antiques and designer pieces.
4. Ebay - Tried and true. It takes a bit of digging but some of my favorite pieces have come from here.
5. Etsy - Not typically one's destination for vintage furniture and lighting but you might be surprised by the treasures you can find!
6. Pamono - Similar to Vinterior
7. Facebook Marketplace - Always a steal to be had!
*If you live in Italy, also try searching Subito