The ad hoc chainfist could really use more bulk. Right now it looks pretty spindly. The autocannon looks spindly too but it isn't designed to be smashed into walls and armored vehicles.
Otherwise the contemptor restyling looks good to me.
The true- scaling doesn't look all that worth it. I think it might make more sense to use smaller discs as spacers. Right now it looks like side of the white plastic is sticking out past the edges of the legs and it should also be easier to fill in the gap with putty and get a smooth finish. Too little putty can make it harder. Also make sure your tools are wet otherwise it sticks to the tools.
The true scaling is certainly not worth it! Its a massive ballache!
On the chainfist, I assume you mean on the upper arm section. I thought that myself, although I'm unsure how to improve it other than just bulking it out with wider plasti tubes.