I recommend a commercial stripper, like Strip-eze. Denatured alcohol takes too long and the result is the same. I even used EZ Off oven cleaner on one and it worked great.
After the shellac was stripped, I washed the stock down with a solution of dishwasher powder and water. Then I rinsed it well and let the stock dry out for two weeks in a 50% humidity environment (my gun room where I keep a dehumidifier). Then, I set about refinishing the stock. I sanded lightly, and then used a 50-50 mix of tung oil and mineral spirits for the first coat. Subsequent coats were 75% tung. The result was a durable finish that looked like new shellac.
If you use a stain, be sure to use an oil based stain, as water based stains are hard to keep from blotching.