Here is what is going on.. A year ago, I jumped on a set of tactical grips and tube extension kit for my Remington 870 intending to turn it into a home defense shotgun. I then decided I didn't want to mess with my hunting gun and have been looking for another Express. I recently got an offer to purchase an older Remington 870 Wingmaster at a good price. It only comes with the field barrel. So my question is... Are the grips and ext tubes interchangeable between the two models? Also, if the Wingmaster is in good shape, would I be better off finding a slug barrel for it and using that as my hunting gun or should I stick with my original plan and try converting the Wingmaster with the parts I have?