Differing Atari VCS case designs

Folks, Got a call from a friend today asking me if I'd like her VCS plus games so I'm now in possession of yet another machine but with 10 or so excellent condition boxed games, some of which I've not heard of before. However it's the machine itself that's interesting as it has a low serial (~70,000) and the case itself looks like what I call the 'US' case - extra thick edges and sculpting on the back where the joysticks etc plug in, not the plain flat back of the models I'm familiar with. I'm guessing it's one of the first UK (ie PAL signal) models since there's no CH2-3 selector switch visible and it has a TV/Game switchbox, but can anyone shed light on why the case was that thick in the first place? Shielding for US emissions regulations perhaps? Cheers! -- Adrian/Witchy Owner & Webmaster, Binary Dinosaurs www.binarydinosaurs.co.uk - possibly the UK's biggest online computer museum www.snakebiteandblack.co.uk - ex-monthly gothic shenanigans :o(