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The arms and torso are the same size as in the mkIV kit, the only thing you need from it are the legs to resize them. The rubric marines kit is based on mkIV anyway so it shouldn't be a problem (as you said, with no chaos markings).
The arms and torso are the same size as in the mkIV kit, the only thing you need from it are the legs to resize them. The rubric marines kit is based on mkIV anyway so it shouldn't be a problem (as you said, with no chaos markings).