I have used Alan Ackley in the past and can recommend him highly. He is reliable and will take the whole thing apart and return it to you better than ever. I inherited my machine when my teacher died, and I had no idea how old the machine was. Alan looked at the serial number and told me my brailler was made in 1961.
I used him a few years ago, and my machine is just fine. http://www.braillerman.com/
Barbara on Long Island