This is an X2 outfit box I recently bought on ebay. It is the 1st time I have seen an X2 set (rare in it's self!) in a black carton! The carton has all the earmarks of coming from the late 20's dark red/green set period with the black leatherette paper and the orange interior. Was there a late run of sets made for some unknown demand? Did it still contain the accumulator that, by 1926/27, had been obsolete and replaced by the Ferranti transformer? Was the motor updated to the current 6 volt cruxiform rather than the fibre side lever 4 volt? All good questions and never be afraid to challenge doctrine! I would like to hear from anyone that has seen another black carton X2 set and opinions of this one in front of us now!