You're so lucky to have found that book! It's part of a series of 10? 15? books, all on old-school sewing techniques. If you can find the rest, snap them up immediately, as they are an invaluable resource. Mys et is currently 9000 miles away from me
If you visit my website (http://rightsidesfacing.efx2.com
), I have a links section on the right called "pattern drafting" with websites that offer more info on slopers. I find drafting my own patterns incredibly satisfying and calming, so I highly recommend getting into it. I would also be thrilled to see more people interested in it, as I'm afraid it's a dying art!