Fixing Blasters Arms

I posted something about this earlier but after watching some videos I have to restate it. The problem with mine wasn't his deck opening. His arms were on backwards. So I assume someone was in there fixing something and put his arms on wrong.
In the videos I've seen he has 2 black pieces that hold his arms in place that rest on 4 total posts. Mine only rests on 2. Has anyone ever came across this? I can't get a tight fit and his arms swing when the screws are on.

In the videos I've seen he has 2 black pieces that hold his arms in place that rest on 4 total posts. Mine only rests on 2. Has anyone ever came across this? I can't get a tight fit and his arms swing when the screws are on.
