Menu:
MicroPlanets Gravity newsreader was released under the BSD license some time back and it is now available without cost. Version 2.7 at least seems to be able to run on Windows NT 3.51 without too much work.
I downloaded the 2.7 zip file (I've not attempted the installer as I doubt it would work) and decompressed it onto the Windows NT 3.51 machine. Without any changes it seems to start fine but the toolbar does not display properly.
To fix the menu bar issue a newer version of comctrl32.dll is required. The Windows XP version of this dll is not compatible with Windows NT 3.51. I grabbed a copy from the Windows NT 4.0 CD (which needed expanding first) and put it in the same directory as the gravity executable. This version appears to fix the toolbar issue just fine.