:Before applying any finish, the stock should be free of dirt and grime, should be "silk" smooth, and should have been stained with an oil based stain. I will assume that you know how to properly prepare the stock, including lifting the grain twice, etc., before applying the stain.
In a glass jar that has a tight lid, mix equal volumes of any marine spar varnish and boiled linseed oil. Add 1/2 volume turpentine. You don't need to mix up a lot of finish, as a small jar will finish more than one rifle. Cut a number of 10"x10" or larger squares of cloth from old 100% white tee-shirts. You'll use these to wipe down the stock. Wipe down the stock with a clean soft white cloth. All applications of the finish are thin, using just enough to cover well. The first 2 or 3 coats should include all inlet areas of the stock. The purpose is to protect it from moisture.
Apply the first coat with your fingers, firmly rubbing the finish into the wood with the grain. Let the stock set for 2 hours. Take one of the folded tee-shirt squares and with the grain, wipe down the stock gently but firmly. Let set for at least 12 hours. Repeat this with 2 more applications. All of the inlet areas of the stock should now be sealed, and application of finish in these areas is complete.
Apply a 4th coat of finish as above, except let it dry for 2 days. Continue the process until you have a smooth, deep, glossy finish. YES! Originals did have a glossy finish! Applying an additional coat of finish every 6 to 12 months will enhance and maintain its durability and beauty indefinitely. "
The above was borrowed from Fred Miller, I have used it on several gunstocks and it is a great finish if the instructions are followed. By lightly sanding/wooling between coats you can tone down the gloss to your liking,and fill the pours in Walnut stocks, I never though it was really a high gloss as per intructions.