Just purchased a NiB Ruger 10/22 w/Mannlicher stock. I've owned and maintained my own 10/22s for years. However, after removing the screw holding the stock to the receiver and centering the safety the receiver/barrel assembly will not lift out. The front swivel mounts below the barrel and the front under-collar is simply decorative and does not attach to the barrel in any way. I'm stumped and looking for answers. Anyone? James1