Some of us prefer Wagner and some prefer Griswold.  I think the older Wagner pieces are just as nice as the Griswolds.  The important thing is that YOU like it.  I have pieces made by Wagner and Griswold.  I am not as fussy about my users, so as long as it is well cast, I don't care who made it.  
As far as seasoning this beast, after it is cleaned, I would warm it on the stove, coat it with Crisco, front and back, then wipe all the Crisco off.  It will leave a fine coating, and then you can use it.  It will season more with use.