Steve: I'm afraid that the wholesale copying of entire articles, even though they are relatively old, would technically be copyright infringement under Section 106 of the Copyright Act. In other words, the authors/holders of the copyrights in those copyrighted works could come after you for infringement unless you can show some kind of fair use defense under Section 107. Courts will look at and balance four factors in determining whether a fair use defense is applicable: (i) the purpose and character of the accused use (here, the use is strictly noncommercial and by a small group of collectors - this cuts in your favor); (ii) the nature of the copyrighted work (here, articles that can be reprinted and sold - bad for you); (iii) the importance of the portion used in relation to the copyrighted work as a whole (here, you're taking the whole article, not just selected quotes - bad for you); and (iv) the effect of the accused use on the potential market for, or value of, the copyrighted work. Of these four factors, courts have held that the fourth is by far the most important. I believe this fourth factor would actually cut in your favor since the reprint market for these articles is small or virtually nonexistent (except for classic bike groups).
Practically speaking, the chances of someone coming after you for copyright infringement, especially in connection with articles this old, are likely slim. However, the more prudent course, although somewhat more troublesome, would be to try and get the permission of the copyright owner before "republishing" (and that's what it would amount to under the Copyright Act) the articles. I would imagine that the authors/copyright owners would actually be flattered to have their articles distributed to the group. Of course, if the copyright on any particular article has run out and that article is now in the public domain, then anyone would be free to copy it, and the law in fact encourages such copying. The burden of proof in this case though would be on the person doing the copying to show that the work is in fact in the public domain.
Sorry for the verbosity, it's what I do. Contact me off line if you'd like to talk it over or if you have any questions. Kevin