C600xxx would probably be a late 1977 model... or a very early 1978 model. Best guess = late 1977 model E (Economy).
You made a good buy at $350... especially if the rifle hasn't been shot very much. Remove and sand the birch stock and forearm down if you would like to stain it with a walnut stain to darken the wood.
After the initial sanding with a very fine sandpaper, lightly wet the stock with a cloth dampened with water to raise the grain or "whiskers". Once the wood is dry, re-sand it again until very smooth... then repeat the wetting down and re-sanding until wetting the wood does NOT raise any more "whiskers" in the wood. That will probably take 2 or 3 "cycles" of wetting, drying and sanding down before the wood remains very smooth after being wetted down.
Stain the wood according to the directions on the container of stain. Once you have gotten to the level of color you wish, you're ready to put the final finish on the stock. Make sure you are starting out with the stock stained the color you wish and the grain of the wood has been "raised" and sanding down until the wood is very, very smooth to the touch. The smoother the wood, the better it will look after refinishing.
Before beginning the Tru-Oil part of the refinishing, you might wish to figure out how you are going to "hang" the wood to DRY since it's surface will be wet with the Tru-Oil and can not be touched or touch any other surface until it's dry. When I did my stocks, I used a small screw and screwed it a short way into an inside part of the stock or forearm that won't have any Tru-Oil put on it and arranged wires hung from over-head pipes or nails in the basement to hold the wood away from any other surface and out of the way of any "foot-traffic" so that nothing would disturb or touch the wood until it had a chance to thoroughly dry.
Once you're wetting the stock with the Tru-Oil, it's a poor time to think of doing something like this... so PRE-THINK what you're doing and make the necessary "arrangements" for safely drying the wood.
Allow the wood to dry thoroughly, then using your finger dipped in Casey's Tru-Oil, smear a very light coat of Tru-Oil evenly (as possible) over the entire surface of the wood. Allow it to dry for at least 24 hours, then using a clean, soft cloth (an old T-shirt or cotton underwear), fold the cotton cloth over a few times, put your forefinger in the cloth and wet the cloth where your finger-tip is with a white sewing machine oil, then dip the wetted part of the cloth in some rottenstone (a fine-grained, light tan powdered abrasive about the consistency of flour), covering the oil-wet part of the cloth and rub the dried Tru-Oil/wood surface with the oil/rottenstone mixture on the cloth until the wood's surface is very smooth. Re-dip the cloth where your finger is in it in the rottenstone or wet it with a drop or so of oil as often as necessary to hold the rottenstone on the tip of the cloth while you're rubbing down the wood.
As you use this combination of light oil and rottenstone, an lightly-abrasive spot of smooth, darkened rottenstone will build up on your cloth. This is desired. You want to build up a spot that retains the rottenstone and yet, isn't "wet" with oil... and becomes a lightly abrasive "pad" with which to rub down the surface of the Tru-Oil and give that surface a soft glow after the wood is wiped off with a soft, VERY lightly dampened (with water) cloth to remove any remaining rottenstone dust before adding another coat of Tru-Oil.
Wipe the surface of the wood off with a water-dampened cloth to remove any remaining rottenstone "dust" and allow wood to thoroughtly dry (an hour or two). Then, using your finger, add another light coat of Tru-Oil to the entire stock and allow to thoroughly dry (24 hours). Do not allow the Tru-Oil to "puddle" or build up any "depth" on the wood's surface since this might create a blemish on the wood's surface as you rub the Tru-Oil out with the rottenstone and oil.
Then, using the same spot of the same cloth as before, lightly wet the cloth with a drop or two of the oil, dip the wetted spot in the rottenstone and rub-out the entire stock smooth once again...re-dipping the same spot on the cloth into the rottenstone as necessary to keep the rottenstone present on the cloth in an almost-dry paste form.
When all the wood has been polished with the rottenstone held on the cloth with the oil, wipe down the wood once again with a slightly water-dampened soft clean cloth and allow to dry thoroughly (an hour or so) before adding another coat of Tru-Oil. Allow that coat to dry thoroughly (24 hours). Then repeat the process of wetting the spot on the cloth with a drop or so of the light machine oil, dipping that same spot in rottenstone and polishing the surface of the wood until you are completely satisfied with the quality of the finish you have put on the wood.
You will find the finish begins to look very good after as few as 3 or 4 coats of "rubbed-out" Tru-Oil. However, the more coats you apply, allow to dry thoroughly, then rub-out with rottenstone and oil, the more the surface of the wood will take on that "soft glow". The more coats you add & rub-out, the more resistant to dents and scratches the stock will become... and the better the wood will look.
I've done some of my rifle and shotgun stocks with as little as 5 coats or as many as 13 coats. Naturally, the stock with the 13 coats looks the best, but after 5 or 6 coats, there is little change with each new coat.
Rottenstone is a very, very fine, light tan, powder-like abrasive about the consistancy of flour. It is an excellent abrasive for doing this kind of work since it will yield a very smooth, beautiful finish that will resist dents and scratches. The finish holds up quite well and will last a life-time with normal care.
Good luck with whatever you decide to do.
Strength & Honor...
Ron T.
