Here's a handy link that indexes several Spidey costumes over the years:
http://www.spiderfan.org/characters/himsel...tume/index.htmlSee, I always thought that Spidey's "armpit web-gliders" were
supposed to come and go. That he'd only add them to him costume as needed. If he's diving and jumping off of buildings, he'll web up his pits and create the gliders. If he's brawling, he'll go without 'em. I always thought they were functional, not decorative.