Ok, first of all, modding the Tieren didn't take that long, like it did to find some time for this post.
I'll just start, without much talking. (I want to post this finally, since new models are waiting for being build).
This is required, since 1 AAA battery delivers 1,5V - in series, both voltages sum up, which results in having 3V, which were required for my LEDs.
This test was followed by soldering everything together - while the series circuit for the batteries worked well, it didn't work for the LED - which resulted in having the LED in parallel circuit. (I don't understand, why series didn't work (and yes, I checked the polarity of the LED's at least 10 times),... well, it works now, but it's still a mystery)
The poseability of the shoulders is not affected by the modding process, i'm still able to move the shoulders for- and backwards, without wires being seen.
Well, next 'to be modified' model kit will be my Sefer Rasiel from the Dengeki Hobby Magazine (January and February issue 2009). The head, arms and the right hand will be made posable. Legs and feet won't be modified, because of the included display base from the Sefer kit, elbow can't be modified, since, according to Dengeki Hobby Magazin, I don't have HG Virtue elbows. Left hand neither can be modified, since the lack of spare left hands. (I only have a right hand of my HG kyrios left, nothing more).
(I didn't checked all my spare PolyCaps yet, but I'm quiet optimistic, regarding this.)