This is a gun sold by Sears, not Browning. Probably valued at around $100-150
Are you trying to refinish the Bluing, The mechanism or the wood? If it's the wood, then it's the same as refinishing any wood product. I suggest you find a book on refinishing wood. It would take to long to answer you here.
Go to gunbrokers.com and do a search, it all depends on the condition of the bluing and wood.
Browning is controlled red rust Fe2O3 and is also known as pluming or plum brown. One can generally use the same solution to brown as to blue. The difference is immersion in boiling water for bluing. The rust then turns to black-blue Fe3O4. Many older browning and bluing formulae are based on corrosive solutions (necessary to cause metal to rust), and often contain cyanide solutions that are especially toxic to humans.
250 USD
The 'X' series was not used on 12ga guns. Please doublecheck your serial number. In any event, the percentages you list would take it out of the collector category and make it a $400-$450 shooter.
Browning uses a hot caustic blue on steel firearms- steel parts are immersed in a hot bath of bluing salts, resulting in the outer layer of steel changing to black iron oxide. Aluminum cannot be blued, and is anodized.
Mrs. Stewart's Bluing was created in 1883.
300-600 USD.
Bluing, as it relates to firearms or metal in general, is a permanent surface treatment under ideal conditions. Poorly maintained bluing will fade or flake off. Bluing is a "form of rust", an oxide layer on the outside of the metal. You can remove it using various abrasives, but yes it is permanent.
Gun Digest (and others) sells books on restoring antique guns. The big tips are to take your time and be careful. You can't put the patina back after you remove it. Go to this site (or eBay) for books: http://www.krausebooks.com/category/firearms_knives 000 steel wool will take the rust without removing bluing.
1977. Value depends on condition. Range from 100-500 USD.
There are several reasons bluing will not take on a gun. One is it stainless steel. Nope. Two is the bluing solution correct. If so, is the temperature correct, Brownells has bluing info for their solutions., follow these almost perfect. Also to be blued, it must be alloy steel. not pot metal, not cast, just steel. Don't get any brass, copper, zinc or lead in the bluing solution. lcjones