Some things in G.I. Joe are almost either unnoticed, or so common that they’re treated as something not worth noting, but in doing that, that knowledge tends to be forgotten over the years, and then treated as a revelation, when someone makes note of it. One thing I’m not sure on how widespread the factoid is, is that in 1983 when Hasbro adopted Swivel-Arm Battle Grip, they did a few things that wound up saving them time, sculpting and money in the long run. They re-used a lot of upper arms, quite frequently.
Basically everybody knows that most of the 1982 Figures, and Snow Job have the same upper arms. Everyone also knows that Zartan, Zarana and Zandar also share the same upper arms (A side-effect of the colour change plastic). However there’s a hell of a lot more than that out there in the early Joe line.
If you look at the 82-83 Swivel Arm Scarlett, and then at the HISS Driver, you’ll notice they share the same upper arms. Those upper arms are also shared with Cover Girl and The Baroness.
Most people notice that the swivel arm Flash and Grand Slam figures, lost the sculpted pads on their upper arms, this was a cost-savings measure as those parts would’ve been used on three figures, tops. The upper arms used by Flash and Grand Slam also happen to be shared by most of the early line. This isn’t a complete list, and there’s a few that I probably mis-identified, but for the most part it’s as accurate as it’s gonna be;
I was actually blown away at how many figures shared those plain upper arms, so I did a little more looking, and found that Mutt, Recondo, Tollbooth and Spirit all share upper arms as well. Surprisingly, Cutter doesn’t share these upper arms, despite having incredibly similar ones.
The final batch of shared arms I noticed were, Dr. Mindbender, Buzzer, Roadblock and Gung Ho. It makes sense they’re shared as all three are bare sleeved.
It’s kind of amazing how much undocumented parts sharing there was, but it was a thing that helped maintain symmetry and allowed for resource dollars to be better spent elsewhere.