The early concept for IG-88 also looks eerily similar to the evil maroon colored robot, Maximillian in Disney’s ’The Black Hole’ . Ralph McQuarrie originally designed IG-88 and then Bill Hargreaves built the character from salvaged material like jet engine parts. IG-88 is literally bolted to the deck of the Star destroyer. Unfortunately after the scene, many of the original pieces were repurposed and scrapped. He was also seen in the scrap room near the pile of C-3PO.

4:58 fortunetly, at least in this case, you're in the wrong. To be more specific, while looking at the thumbnail, I got a feeling of "deza vu" (even tho I never thought or knew of "IG88 Prototype desighn"). And them it struck me, I remember this droid desighn, it was used as bodyguards for Vizago in Star Wars Rebels show. Heck, while looking for info, I even found a review of Rebels toys, including this droid.

Music at the end is a bit loud, but otherwise very fascinating video!