SINGER 31-15 - Heavy Duty Industrial Leather Sewing Machine 1. This is one of many vintage sewing machine I've just listed for sale that were used at a company that went out of business fairly recently. I was told they are all in working order, but I have no way to test them. Please feel free to ask any question. Please view the pictures to check the cosmetic condition, to see what is included and/or to check if anything is missing.Happy to help any way I can. The item "SINGER 31-15 Heavy Duty Industrial Leather Sewing Machine 1" is in sale since Thursday, May 04, 2017. This item is in the category "Business & Industrial\Manufacturing & Metalworking\Textile & Apparel Equipment\Sewing Machines". The seller is "leadoff" and is located in Greensburg, Pennsylvania. This item can be shipped to United States.