I watched that last night- ineresting that they make them in batches of 15 pieces.
According to Wiki, "The DL103 was designed for professional
broadcast use in 1962 using the arms and
turntables of the day. Production has continued uninterrupted since then. There are available different versions upgraded by other companies or individuals involved in
DIY audio."
I have a 103d, which I got in a trade in about 1981- it's great, but the low output makes it a bit difficult to find a suitable MC phono preamp, at times.