I have owned a 523 since 1970. It sits in a wooden cabinet and converts fron electric to treadle ( I lived in a country where power outages were the norm). When I came to the US I had it shipped and it is still a very dependabe machine. Today I use it mainly for piecing but it is still my favorite machine. To get a manual or more info, Google Necchi and then search for 523. Also www.sew4less.com carries some parts.
Hope this helps!