Name That Sounding Rocket: Starfish Prime Shot

Hey all,
I was watching the slideshow that NPR put together on the Starfish Prime test shot (https://www.npr.org/templates/story/story.php?storyId=128170775) and couldn't help but notice the sounding rockets they were using to probe the blast, about 25 seconds in. The first stage is definitely an ASP -- RotW says it was the de-facto vehicle for sampling atomic blasts -- but any ideas on the second stage? It appears to have the CDC/Marquardt sticker on it. "Small Sounding Rockets" lists a two-stage ASP configuration as the ASCAMP, with a Sergeant vehicle atop the ASP; could this be it?

The slideshow is really cool, btw.

Thanks in advance for any help!

6.5" diameter scaled-down Sergeant (Cooper RM-3141), original designed by JPL. I believe it's the same motor used in the Jupiter-C's top three stages for Explorer-1. Cluster of 11, staged to 3, staged to 1. About 1700 lbs for 6.5 secs, polysulfide/aluminum/AP. Something like an 18% P7500.

Edit: aka "Baby Sargeant".

-John