I have a benelli m104 and am looking to swap out the stock tube so i can have my collapsable stock actually collapse! I recently found this site ww.e-gunparts.com/DisplayAd.asp?chrProductSKU=983200&chrSuperSKU=&MC = but am not sure if i need the whole tube assembly for $98.25, or just the tube for $54.55. Also can anyone tell if that is a 3 position or a 2 position? I'm looking for a gunsmith to swap them out on my gun but am nervous having someone do it if they haven't done one before. I live in allentown, Pa does anyone know of a gunsmith close to me who has the ability to do this without messing up my gun?