Rather than revert to the alchemy of boiling wax (sans safety goggles, I'll bet) like some of us did 20-30 years ago, just use modern technology to best preserve those old chains. Whenever I measure chain stretch on my heavy use rider, I just don't find that I have any because Prolink, used obsessively, works. Not any wear on my DA Ti cogs, either. If you want more info, check out archives on cyclingforum.com.
Ken Wehrenberg, Hermann, MO