I restore old Teletype machines as a hobby. Only WWII and earlier machines, ones that are much older than I am. The oldest machine I have is from 1926, and it's fully restored. It's currently in my living room, hooked to a Reuters RSS feed via a USB to Teletype converter I built and an old EeePC subnotebook hidden away in a cabinet. Push the button and the current news prints on a long paper tape.

A completed project: http://www.aetherltd.com/refurbishing15.html

A project in progress: http://brassgoggles.co.uk/forum/index.php/topic,43672.0.html

There's a hobbyist community restoring these machines, and full maintenance documentation is available. Restoring them isn't too tough. They were designed to be maintainable. The guys who try to restore minicomputer Teletypes from the 1970s have more trouble than those of us restoriong the 1920s and 1930s designs.