If I were to create an Enoch, I would buy a ROTK to base it on, to get the dimensions right!
The shins, thighs, biceps, forearms and the AB is hard to say that it isn't parts directly from a ROTK, and one of the things I've felt most of the time when I see builds is that the way the AB is being printed is off in the dimensions, the buttons on the AB seem too large, and the bottom edge of the AB usually ends too far up above the belt (or it just looks obvious like that because the printed dimentions are a bit too large, leading to when you tighten the belt around your waist, your waist looks much smaller than the AB itself).
I think that it's just the normal ROTK armor that they've gone for there (AB), and cut it so that the belt tightens on or near the bottom edge of the AB and not completely below it.
On screen grabs I find it hard to say for certain that the AB would end above the belt.
The shoulders look a bit wider than the normal ROTK and seem to have a different curve
The chest as you say and know about is most likely not a direct child of the ROTK chest.