OK, so it was removed from a R-4C (last pic) and it looks like it might be a homemade unit.  Was there ever a "make your own NB" article in a ham magazine years ago that came up with this circuit?  Note that it has 2 IC's in it (MC1350P).  One of them is a bit loose in its socket, but I am deathly afraid of anything with 3 or more leads that has bits of silicon inside and could easily be destroyed by heat or looking at it the wrong way. I have no fear of high voltage tube transmitting stuff that can kill you, but this little stuff, no way!
    As far as does it work or not, NO it's not doing anything. With it in the radio, no signal will pass thru it in either "on" of "NB" positions, but I did hear something briefly (intermittent someplace?). When I made up a jumper plug to bypass it, the radio came to life.  
   Soooo, I'm not going to fool with it.  It may work great with only a minor issue.....or not. Do you feel lucky? Is it a rare prototype of some sort? No idea!

Thanks to eBay's current draconian policies regarding returns, and parts changers, "renters", scammers, etc, we will no longer sell most items as working, but rather "officially" as parts, not working. Also thanks to the same policies, we will no longer ship directly to any country other than the US. Any overseas buyers must buy thru the ebay shipping program.
The purchaser, upon receipt, might not agree as to my assessment of condition, but that's what it was HERE in MY opinion and it's being sold officially for parts or not working. It may or may not work at all when you get it!   NO REFUNDS or RETURNS!  If you don't agree to these terms DON'T BUY IT.