Thats rather interesting. I am a souvenir addict. As it stands, I am working through level 24, have jut been given all my level 25 contacts (they wont give me any missions yet), and I have:
Souvenir update: as of lvl 22 I have the following:
Skull Bandana - Hellions and Skulls
Water Dept ID Badge - Vhaz
Etched Peice - Clockworks
Damaged Powersource - Clockworks
Rage Ampoule - Tsoo & Trolls
Hypodermic Needle - Vhaz (including Doc)
Tsoo Dagger - Tsoo, Family and Warriors
Iron Hand's Badge - Freakshow
(and I blew the Wheel of Destruction last mission - Banished Pantheon).
In checking around both the boards and with other players, it seems it really doesn't matter what origin you are, all players can get these story arcs. Not sure why so many players seem to miss them unless the just advance past them without realizing it. Being a primarily solo player, I always attempt to do every mission I have (no matter what the foe group) so as a result I dont think Ive missed any. One nice thing about completing one is I believe you get a reward on top of the reward for the normal completion of the last mission; i.e. when I finished the Tsoo dagger last mission, I got a double reward of 1600 exp and influence.
My main dissappointment is that there really aren't very many overall arcs. From what I've ready they tend to taper off the higher you go so if you get them all you might end up with 16-20 or so total.
To me, this would be an easy content add for cryptic; a lot more story arcs with souveniers at the end, else every character will get the same ones if they choose to pursue them. Heck just rip off half a dozen comic book plots. Since the missions themselves aren't that different from a one of mission, it seems like it would just be some story writing and linking.
Like the story arcs; just want more, lots more (like 20 per origin instead of 20 total in the whole game).
Xilren