Yea,,, that looks familiar,,,
The supplier sold parts for thousands of them,,, all over the world.
If you are worried about twisting the arm,,,
when it picks up the telephone pole,, the heavy end is on the non-arm side,,
Here is a video of it operating, on a 149,,,
https://youtu.be/eTjuozhzwBc?t=15m25s
Here are some customer pics,, do not blink,, the pics go fast,,,
https://www.youtube.com/watch?v=Sks3k9-FONk