My neighbors have done leather repair as a business for decades..they are in their late 60's now. She uses the old Singer treadles ...he uses Chandler electric machines. Between them they must have 10 machines set up in their sewing room for different projects/applications. If you have more detailed questions, I'd be happy to ask them for you, but as for machines, that's what they use. BTW...the Chandlers are all over ebay, I look for them occasionally as they are not internet users and sometimes need a part.