I got a Pardner Protector the other day and ordered a Hogue front grip for it. I ordered one for the 870 since I heard most of the parts swap. Also, I watched some videos on youtube where others had swapped out some various parts.
The Hogue was a super tight fit. I had to use a wooden block to "help" it go all the way on. It was so tight the spanner nut wasn't really necessary but I put it back on anyway of course.