The only legal way is to get permission first, directly from those who hold the rights. Unless you get express written permission, don't sell knock-offs. Do your research and you might find that some of the mid-century designers will grant a license for replicas, but you will need an attorney to complete a licensing deal. Be sure to include these legal costs in your budget.
This comment is NOT LEGAL ADVICE and is posted for informational purposes only. I am not your attorney; you are not my client. Both you and any other person reading this comment SHOULD NOT RELY UPON this comment. Regardless of the information provided in this comment, any reader of this comment should CONSULT AN ATTORNEY to get the legal advice you are seeking.
In light of my colleague's responses, a devil’s advocate is needed here. In short, I think it very likely that much of the furniture made in or around the 1950s is not protectable under any body of intellectual property law. And if some elements of that furniture is protectable then there’s likely a lawful design around.
Copyright: Functional items are not generally copyrightable. An exception is only to the extent that a design “incorporates pictorial, graphic, or sculptural features that can be identified separately from, and are capable of existing independently of, the utilitarian aspects of the article.” So while a dresser is not copyrightable the swirl design on its drawers, for example, may be copyrightable. But the controlling law would be the 1909 Copyright Act and that law requires formalities and renewal registrations for copyright to apply.
Design Patent: Furniture can be protected by a design patent. But in the 1950s it was not customary to patent furniture and if any were patented then they have long since expired.
Trade Dress: The fact that furniture is inherently functional dramatically limits the elements of the furniture protectable as trade dress [only the ornamental features qualify]. And because those elements are part of the product’s design the manufacturer would have to establish that those elements have developed secondary meaning in the marketplace.
Trade name / Trademark: It’s lawful to use the name of the manufacturer or designer to inform consumers that that manufacturer or designer was the source or creator of the furniture [so long as that is done in a way that does not state or imply source, sponsorship or endorsement].
So what “rights” does a 1950’s furniture maker have left? None that I know about.
Questioner, I think you should discuss this business plan with your own intellectual property attorney. You may – just may – be able to lawfully do what you propose.
The above response is general information ONLY and is not legal advice, does not form an attorney-client relationship, and should NOT be relied upon to take or refrain from taking any action. I am not your attorney. You should seek the advice of competent counsel before taking any action related to your inquiry.
You are asking lawyers how to help you engage in illegal and potentially criminal misconduct. There is no "legal" way to do what you are proposing. Indeed, you risk criminal prosecution for even having submitted this question on AVVO, a public web-site monitored by law enforcement. You need a license from the designers or manufacturers of the furniture that you propose to sell on-line----and you have an absolute legal duty to assure that you sell only authentic pieces of furniture. Selling counterfeit furniture is illegal and can land you in a federal prison.