JRS, contact the American Philatelic Society. The library will make you a copy of the article (there is a cost for it, but not much) and mail it to you.
I don't think you have to be a member. However, if you are serious about collecting, I highly recommend becoming a member. There are many advantages.
When you reach 50 posts, send me an email if you are interested and I'll be happy to sponsor you.