![Image](https://img00.deviantart.net/0c8e/i/2018/191/5/e/rotf_leader_megatron_right_arm_mods_05_by_zeldatheswordsman-dcguzvi.jpg)
So, I got the fingers mounted with twist ties like I mentioned, secured nicely with Krazy Glue. They can fold away from the cannon muzzle, and then fold back into place. Twist ties also served for mounting the posts that steady and support the upper pincer halves when they're in the closed position.
The pegs that anchor the claw halves in their tank mode/"open" position, and the sockets they go in, should also be visible.
I also got some basic hinge struts constructed. Not the best looking, but paint would have probably helped with that. However, there were clearance and function issues with them. And so I have abandoned the idea of hinge struts until I can make or source some better ones.
![Image](https://img00.deviantart.net/ba98/i/2018/191/3/d/rotf_leader_megatron_right_arm_mods_06_by_zeldatheswordsman-dcgv0ph.jpg)
Instead, I have resorted to using twist ties for that purpose as well. They're not the most elegant, but they at least work reliably. You can also see the elbow jointing at work.
![Image](https://img00.deviantart.net/6a68/i/2018/191/f/2/rotf_leader_megatron_right_arm_mods_08_by_zeldatheswordsman-dcgvt9a.jpg)
Because of the elbow joint, I had to move the tab on the upper arm that secures the flattened pincer assembly. That was a bit of a pain, but I got it migrated forward sufficiently.
![Image](https://img00.deviantart.net/7a0f/i/2018/191/7/a/rotf_leader_megatron_right_arm_mods_07_by_zeldatheswordsman-dcgv22a.jpg)
And a tank-mode shot, showing that it can still transform back to this configuration just fine.