Information about your wonderful family gift is on this page http://www.lcsmith.org/shotguns/pre1913grades.html Scroll down to O grade and the E stands for ejector. The crack is a real concern and must be repaired before you use the gun more. The smith may also want to glass bed the head of the stock and around the side plates to prevent further wood damage. Let us know in what part of the country you are and we can recomend some good wood specialists. Certainly your gun is due for a good check and clean by a doublegun specialist smith also and we could give you some more names (some of whom could also do the wood repair) And yes, your fine old gun now has 96 year old wood and I would shoot nothing stronger than the Winchester AA Xtra-Lite 1 oz target load. Another excellent choice for skeet would be one of the following: By Federal for MidwayUSA: 7/8 oz load Muzzle Velocity: 1200 fps Chamber Pressure: 5000 psi http://www.midwayusa.com/static.exe/getstaticpage?page=11120061_page.htm
Another option is the Fiocchi 7/8 oz 12g load FC AMMO 12ga LITEd 7/8oz 1200fps #7.5 250/cs Item Number: FC1278OZ75 Available at Graf & Sons for $50/case + shipping http://www.grafs.com/fc/browse.php?o=5&p=387&q=&v=&s=
Take care of this family treasure and your great grand children will be enjoying her also