I had a 12g version from around the same period as your gun. My recollection was that the finish was unfilled in the grain and maybe even not completely sealed. If this is the case, steaming with finish on may work. However, be prepared to have what finish is on there to become milky and take the impression of the fabric. That said, it may still be workable without removing all the finish. I believe it is not a catalyzed finish. The problem with the field grade Citori's is that they all seem to have been stained. If you elect to remove all the finish and refinish the buttstock, it will require restaining before finishing. I believe the finish is reproducable with something like a few thin coats of Tru-Oil.
