I don't have a Spyderfly, but the best place to buy pivots is probably
USAknifemkersupply, run by Tracy Mickley (a regular of the forums and a standup guy). Knifekits.com also has pivots (or any of the other supply places.)
Can you post a picture of the pivots? Can you measure them? Standard sizes are 1/8, 3/16 and 1/4", I would guess that the Spyderfly uses 1/8" but I have no way of knowing that for certain...