Arthur
regards sleeving the barrel...you can fit a sleeve that does not weigh the same as a 98 one, and the gun is way nicer for it. I find the 98 sleeve way to heavy, and yet the sleeves i make for my rifles are way nicer.
The trick is 20mm OD 16mm ID tube, forget silencing the 16inch barrel just finish the sleeve flush and only go 50 to 70mm past the end of the barrel on the 12inch version.