K, thank you for your question.
With eez.io you don't have to worry about overselling your one of a kind vintage pieces. All eez.io stores come with inventory management system that can be used to assign number of items available in "stock".
You can assign number of products available in stock from any product page: "Product Settings" -> "Shipping" -> Quantity or from the store Settings menu - >Stock tab. In case of unique vintage goods it should be set to "1".
When all products available in stock are sold, the inventory mechanism will prevent your store visitors from adding them to the shopping cart and checking out.
Please let me know if I answered your question and if I can be of further assistance.
Anne - eez.io support