Not a double gun, but I am asking because of the knowledge on this board. I was given a nice little Wincheseter Model 1906 pump .22 made in 1910, and it came broken down in a very handy little canvas and leather case from Abercrombie and Fitch. The canvas needs cleaning and the leather is dry and cracked. Any guidelines or tips for cleaning, stabilizing and rejuvenating this little gem?