A vintage leather sofa is similar to an antique sofa in that it's old; however, a vintage leather sofa has been kept over the years and still remains in great condition. It's the difference between buying a 1967 Mustang that looks and runs like a 1967 Mustang, and one that has been restored and runs and looks better than the 2010 Mustang. Leather is the easiest type of vintage sofa to find because it's the easiest to take care of and restore if something ever goes wrong. With fabric sofas, moths and dust and things get to it that rots it and microfiber hasn't been around long enough to be considered vintage.
On your quest for a vintage leather sofa the first place that you should look, the most obvious place is the antique store. Antique stores have items from all around the country, when people moved to that area and sold stuff, people who were leaving that area and sold stuff, and if someone passed away and their loves sold their furniture (not that you'd want to know if that's how it got there). Antique stores have the best variety of leather furniture for the cheapest price, and because antique stores are generally owned locally you can probably talk them down to a more than fair price if you find something you like. Pawn shops, antique road shows, and auctions are also a good way to find vintage leather. A lot of people don't know the value or worth of vintage leather so they are happy to sell it for next to nothing not knowing they have a pot of gold.
Vintage leather is tricky, because you can't go to your closet department store and get a real vintage leather sofa. You can go get one that is made to look like it's from the 1930's or whatever era you desire, however it will probably have been made in the year you're buying it in. That's something you should consider; if you want a real vintage leather sofa, or one that's just made to look like it's vintage. With all the sophisticated technology and machines that are in use today, it's not hard to make a replica of a vintage leather sofa; the main difference is going to be the price. If you're looking to buy a genuine vintage leather sofa don't be surprised when the asking price is more that $10,000.
Another thing to keep in mind, when purchasing a vintage leather sofa is that the color options aren't going to be a whole lot. A lot of sofas from the earlier years are browns and deep dark colors. There was no such thing as bring yellow and orange leather back then.
Taking care of a vintage leather sofa is not super easy. Vintage leather sofas are really made to look at and not sit on or use regularly. With traditional and modern leather sofas you can just use natural oils to keep them looking healthy. However, with vintage leather I may be a whole new ball game. It would be wise to ask the person you bought it from how to take care of it, how they've been taking care of it. Vintage leather more than likely has not gone through the processes and treatments that modern leather has gone through so it may need special oils to keep it looking new and to last as long as possible.