The original '05 Ego had a one piece barrel. The actual Nexus Ego was an '06 model with a two piece barrel. A regular '05 barrel will be cheap, the '06 two piece will be harder to find
Up until recently I had a pristine '05 Ego in Platinum. Nexus used them before the team editions were cut.
Keep in mind the release cycle Planet used to have - the '05 Ego actually came out in 2004, the '06 came out in 2005, and so on. New markers were released usually at World Cup each year.