I do not know.
But the pardner was out before Remington bought NEF.  
But it does look very similar in dimentions.  I like the slight hump back.  Reminds me of a Stevens 520 Pump gun.
But the 870 is popular and it would make sense if they did make the gun to use those stocks.
The only times I have played with the Parnder was a Sports fair I was working, a shooting gun show,
and NEF sent us NON firing guns.  the bolts had no firing pins or holes to put the pin into.  Was a little frustrating for some of the people at the show that wanted a good cheap pump gun.  I have been toying with the idea of one as a rifled slug gun for a while.
If I get one I will see if the stocks from my 870 will fit and work.
ANd yes the rifle version is cheaper to buy as a gun than a rifled barrel for either my 870, 1100, or Benelli Nova.