This link might be relevant to you:
http://www.tfw2005.com/transformers-...nus-bust-4500/
Excerpt of text: "Exclusive Hard Hero "Stealth" Cyclonus Bust has been revealed. This bust is limited to 100 pieces and was the last Transformers bust produced by Hard Hero. TransformersCon was able to track down this previously unreleased item so both attendees and non-attendees could complete their collection."
My guess is that TransformersCon somehow acquired the busts from the above mentioned Comic City.
