If you google Jones sewing machine it brings up tons of links! Even a historical account of the conception of the machine. I did find this info on a site that is in the US. I've never heard of the brand otherwise and have never used one so I'm sorry I couldn't give you any really helpful info!
http://www.jonessewing.com/"Jones Sewing Machine Co. UK
Aside from sharing the same name, there is no connection between the prestigious manufacturer from the UK and our operation in Peoria, Il USA.
A Jones Sewing Machine is a high quality product and vast numbers survive to this day. They have been out of manufacture for some time and sadly, such things such as manuals, belts and other supplies are no longer available.
We are quite willing to help but we need a lot of information with your inquiry. Photographs and descriptions will help greatly as model numbers are of little value."