I don't know anything beyond what I posted. Try sending email to Brandon Wilson, bwilson@somervillema.gov or Kristen Stelljes, kstelljes@somervillema.gov. (Or phone them at City Hall, 617-625-6600.) If you find out more, please add another comment here.

The tower would need to be staffed if it were open, since the stairways are very narrow and can only accommodate people walking one direction at a time. There's also a very limited amount of room for people to stand at the top.