Not sure if this should be here or in the customs thread.
I bought a G1 Scowl missing one arm. A Universe Legends Starscream arm is about the right size to fit.
I trimmed it, mixed up a blend of purple to match and voila.
It's not perfect but it does the job at a glance.
(still figuring out Imgur's new sizing protocols)
First attempt. Arm stuck out too much for my liking.