Card is the same (as is the given date of 2006 - so clearance!) and number of figures/layout on the card is the same, but we have a catapult in place of the gun and the six ex-Esci poses.
As you can see the cradle/frame is the same machine, with the trigger and mounting brackets we saw the other day, however, the rest for the gun-barrel is absent so it would seem that the change was made to the mould-tool halfway through the production run?
Brian's 'big bag' presumably carries all the figures and both siege-engine types? Which will be something to look forward to in Plastic Warrior magazine and - painted-up - on his Blog maybe?