And well...obviously the truth lies somewhere between Butters and Garlic (as strange as it sounds
Well, it may not be too far off and it seems he also leaves room for improvement, so that's cool. When Hot Toys say they want to make a T1 endoskeleton, then they should make a T1 endoskeleton. Otherwise, what's the point of calling it a movie specific endoskeleton and not just a generic endoskeleton. They are aiming for the T1, so they should go find reference for the T1.
Going back and re-evaluating my thoughts with Butters comments about the proportions being right, I tried finding a picture of the fourth scale that matched that original endoskeleton in Japan. Couldn't find any, so I photographed my Hot Toys T-700 in approximately the same stance and tried overlaying them. Sure, it is not a perfect comparison, but I found that if I scaled the T-700 so the legs fitted, then only the arms also fitted, while chest, spine, pelvis and head was too small. When scaling things to match the head and chest, then arms and legs where too big. So the HT T-700 - which is basically the same as their T-800 - is ill proportioned and I'm seeing the same on the fourth scale.
Too small head and chest in comparison to legs and arms, compared to the original.
If they get the proportions right, I can probably overlook the other details, and just consider it an awesome endoskeleton and not movie specific... but if they really want to hit a home run with a T1 endoskeleton... then the details mentioned by P and some other details of the skull, no knee caps, + the groove and the neck added mentioned by Butters would be perfect.
This is just a quick, crappy, poor work comparison, showing the HT T-700 scaled to the original endoskeleton, so that the legs match. You can see how "skinny" the torso and head looks. I widened and relarged the torso, pelvis and head, but didn't mess with the too much gap between the pelvis and torso (if I had, the comparison would have been better). But they need to make pelvis, spine, chest and head bigger, at least on the sixth scale. I know, I know, this is a thread about the fourth scale, but to me it just looks to me like they upscaled their sixth scale, so the comparison holds in my mind.
Again... this is super crappy photoshop work!!!!!!