A late example of the Riveras sold by Thomas Cara, Ltd. of San Francisco.  This one from the original owner. 
 
All chrome model in very nice overall condition.  Some plating loss under the drip tray grid, and one spot on the edge of the drip tray.  (Zacconis have become notorius for bad plating that gradually peels off, so if you're not down for some vintage Zacconi "character" on the bases, you should avoid them!)
 
Unlike the bases on Zacconis, the spring loaded groups, the lever handles, and the boilers themselves have really beautiful, deep chrome plating.  
 
One of the few "home" spring loaded levers, the groups are very similar to the Elektra home levers.  Like most home levers of this vintage, the filter baskets are small, like Pavonis, so know the shots will be about "half" the size of of full sized commercial portafilter.  
 
These classics are getting harder to find, and Zacconi is not making spring loaded Riveras anymore.  Be warned not to burn up your heating element either, by running out of water in the boiler, since Zacconi is no longer selling replacement elements.  (We're working on a "fix" for that, but haven't gotten there yet!)