Arms
Out of the box, the shoulder and the upper arm are one piece, but Bandai managed to retain its mobility by cheating with moving lower arm instead. But if you're a purist like me, you'll not put up with that! I separate the shoulder and upper arm, then poly-capped the arm and pegged the shoulder with corresponding plastic rod. Now you get a removable and rotatable upper arm.

I hid the ugly poly-cap between upper and lower arm by using a trimmed GP-03S part (see pic). The hands here are Kotobukiya's metal hand pegged through a drilled square vernier piece used as a cuff.

Arms diagram
1. 3mm plastic rod
2. poly-cap is planted inside using polyester putty
3. A part joint cover part from GP-03S kit
4. A small vernier part use as a cuff
5. Light crystal (the red part)

1. 1mm coil spring and brass pipes
2. Vulcan
3. Large minus-mold
4. Small, drilled flat rivet
5. My detail thingy
6. 2mm coil spring and brass pipes
7. photo-etch
8. Burner
9. Rivet
10. putty textured and small rivets
11. Back of the knee pad: plastic sheet and photo-etch
12. Photo-etch, minus mold and texture
13. Rivet
14. Damage mark using hobby knife
15. Kotobukiya's white metal hand