The second TR-48 is located in Padova, Italy at the Friends of the World Treasures Computer Museum which is operated under the auspices of UNESCO.
The third is part of the Digibarn collection in California. They have pictures of their machine...note the delivery truck with a lifting gate and the nice pnuematic truck they used to bring it into the barn. We carried ours and almost ruined four backs!
For more information, click on the link(s) below.
National Computer Museum: Bletchley Park, England
FWT Computer Museum; Padova, Italy
DigiBarn; California, USA
If you know the location of any other of these, please let us know by contacting us at info@EarlyComputers.com.