Super Nova Comfortech to Pistol grip

[rhodesengr]

I have an SN with a Comfortech stock. This one particular

 

I switch back and forth between stock and a more "tactical" setup. I would like to add a pistol grip. I have found two possibilities. Benellli has this one

 

and mesa Tactical has this one:

The Benelli one description says "To install this stock you will need a stock swivel plate (60343) & a recoil spring tube plug (60426) which are not included." I have looked at those part numbers and am not sure where they would go. Are they really needed? Is there a diagram showing where they go? Does the Mesa Tactical one need those parts also?

 

 

[Major Woods]

I have Benelli factory one installed on my Supernova, I did not add any additional parts during install.