Missing Concept Art #24 -- Help

[JƩR3M¥]

So here's the deal. I've finished the single-player game. I've grabbed up all the collectibles I can -- gold, records, toys, etc. I've scoured every one of the Ubercommander missions to pick up what I missed previously. I've used the official guide, YouTube videos, and a few guides to be found here. And here's the problem:

The only collectibe I'm missing now is Concept Art #24. I looked it up in the guide, and the only place it appears is when you're making your escape from the Roswell labs, after you've placed the nuclear bomb in the reactor.

Concept 24 very easy to miss, and even worse, it's in a section of map that doesn't seem to appear in any of the Ubercommander missions. I've just finished playing through the Riverside Ubercommander mission, and I didn't see it there, either.

Does anyone know of any way I can pick this thing up without having to start a new game and wipe out all my progress so far? Does it appear somewhere else I haven't looked? Or am I up the creek without a paddle?

[JƩR3M¥]

Never mind...I found it...

[Stun]

Where did you found it? I have the same problem...

[JƩR3M¥]

I'm going from memory, so bear with me.

I THINK you'll find it in the first control room after the catwalk, after the Riverside Uber mission begins. It's on one of the countertops right in front of the big bay windows overlooking the bay below, where you find a pair of troops, a pair of droids, and a cargo sled.