All the parts needed for the entire backpack, just 42 (two for the fuel tanks and 'wings')
The synchronized expansion of the thrusters and the armors is a huge selling point for this MG, and I used to think that it would be as complicated as those backpack action for SEED Destiny MG. Didn't expect it to be that simple really ^^;
Simple, but very effective.
Few number of parts for the backpack isn't a bad thing actually. It helps to keep its weight low so that it won't drag the model down from behind. Plus, the joints would be much durable too. *cough*MG Strike Freedom*cough*
But for those who are looking for a lot of challenges in assembling Gunplas, does this disappoint you? ^^;
Images from Gunpla Secret Base.
A comparison with MG Shin Musha:
Red vs red! ^^
Image from Apron Model Production Diary.
3 days till its official release! ^^