Well,
Honestly, it is hit or miss, some people have success, others not so much!

They like to SNAP, when straightening them.
If I were you ( not telling you what to do, just offering ideas )
There are several options.
They sell new replacement parts ( eBay, ect. )
They also sell new ( cheaper ) plastic replacement parts, honestly I've never messed with them myself, but see people using them with success.
Sometimes you can find a complete roll section, motor, arm, board ect, just screw it together plug it in then go. ( this will save some disassembly )
Now if you want just the arm, to swap your parts with, I personally would just replace, but post here in classifieds, maybe someone has a spare? Or cal local repair shops for used but good parts, maybe even free? I also have a friend, who supplies all my parts, great guy, great prices, and guarantees his parts. ( he is always cheaper than the rest. ) if you cannot find one for a reasonable price, he is the guy.
Feel free to call him, if you want.
Mike Holt
530-277-5366
He is in California,
Tell him Jerry from Florida sent you, he will help you.
Hope this helps!
A+
@msinger, you are always good for a helpful video!
J Dot
Take care, and good luck!