That artwork looks awfully familiar. Anyone out there got a collection of old copies of Avengers?
 

According to Scott Shaw, the ad was possibly drawn by Kirby himself, instead of just being a knock-off of standard Kirby-esque poses. Which isn't to say that by 1976 Kirby wasn't willing to recycle older stuff for this kind of commercial make-work (not that I'm saying he was, understand).
 

Now that I see the ad after so many years, I'm pretty sure I had Dr. Steel, The Whip, and Big Jim.

I know I had the bald guy with the chrome-colored hand, he had a button on his back that when you pressed it, he did a karate chop. I'm pretty sure I had The Whip, I remember the boomerang bandolier. And I'm pretty sure I had Big Jim himself, I remember his arm-band communicator with the razor spikes so he could slash someone's neck while talking on the phone.

If I remember my action figure army at the time correctly, they were smaller than GI Joe (with Kung-Fu Grip!) but bigger than the Mego guys.

PS, if you haven't seen it yet, more pictures and news about the Legion cartoon series at my Legion Omnicom blog.
 

Your mention of chrome hands reminded me of one I'd forgotten, my Bullet Man! (And it was GI Joe's Adventure Team, not Action Team, the latter being the version sold in Germany, it turns out.)

Did Big Jim really have the ability to cut someone's throat without even hanging up the phone? Awesome.

And oh, yes, I've had your Legion blog on my bloglines feed for weeks now. I crave any news of the new series, and a one-stop-shop is much appreciated!
 

The ad itself may not be by Kirby, it's obvious that it's swipes from the box art that the King drew.

Mattel recycled that artwork in Mexico as well where it went through some weird changes.

For the second series of pack, they used John Buscema.