As long as you are using apparel weight leather, a vintage machine with a leather needle is fine. My DH is a leather worker. I started him with a 1960’s white machine that I didn’t care about. It worked ok, but I eventually found an industrial pre WWI needle feed machine on Craigslist for $300. It does a nicer stitch, and longer stitch, but I would only recommend the industrial if you are going to do leather work regularly.