It was then opened (see below, layers of „epic scale“ stuff – as it said on the tin over 2,500 figures): 

Both armies albeit looking very similar apart from the colour of the sprue (see below, it also has to be said that figures for General Meade and General Robert E Lee also came in the box):  

Exciting as this was, the „bonus“ was the A5 Black Powder Rules Book which means I can justify other Powder Era (Napoleonics, AWI, Malburian, Colonial) 28mm long standing purchases as „waiting for this time“! Ancients and Pike and Shot are still slightly awkward to justify .. but I have „adaptable“ rules for those.