The Atari 4160 STe is an Atari 520 STe with 4 MB of RAM. It was never marketed and was built by Atari for the developpers. It had a special version of TOS, version 1.6 (the Atari ST Operating System), with less bugs than in the final version !
The machine itself is just a regular STe with 4 1MB Simms, which although expensive at the time, were quite commonplace.
The badges can be bought from eBay, so seeing one of these machine for sale is no guarantee that you are getting a ''Genuine'' developer example.
I own 2x 4160STEs, but as for provenance, they have none, since they have been assembled from parts bought from eBay and other sources. As has been said, a 4160STE is just a 520STE with 4MB RAM. You can even still buy original, NOS 4160STE case badges, so unless you have documentation that proves it to be something special, I wouldn''t take it as read that it''s anything other than an upgraded STE.