Well, we KNOW that 2 Kalimars were used, as we can see the 2 lenses. And we know that 2 Seagulls were used for the big side knobs. That´s four little knobs of each version we know for sure.
When 2 Kalimars and 2 Seagull knobs are used on the Stunt, then what is left for the Hero? Sure, there may another Kalimar have been available, but if they did, why don´t use more than just the little knobs, and don´t use just the already remaining 2 Seagull and the 2 Kalimars?