Thank you for the welcome and the quick replies.

I understand now, it was a matter of targeting. So I believe we played it out correctly by allowing his Seeking Dispel to remove my Reverse Magic without revealing it or paying reveal cost.

Beastmaster with a revealed Harmonize Spell, cast a seeking dispel on my Wizard with a face down Reverse Magic spell on it.
  Seeking dispel says "Destroy target hidden enchantment. Controller of target enchantment cannot reveal the enchantment once Seeking Dispel has been cast."
BUT
Reverse Magic says "When this creature is targeted by an incantation or enchantment spell controlled by an opponent, you MUST reveal Reverse Magic (for 5 mana) during the Counter Spell Step. You take control of that spell. Redirect it back to the caster, who now becomes the target of the spell. If the spell cannot target the caster, it is countered. Then, destroy Reverse Magic."

Seemed like a logic loop so what happens? Do I pay 5 and discard it because he has no face down enchantments or does it simply get countered? Or do I cancel his Harmonize?