Dark Mech Marines Advice
I've been kitbashing a CSM army to play as Dark Mechanicum starting with the Wrath of the Soul Forge King box. Originally I was going to include some Iron Warriors for marine units, but I think I like the idea of converting the Dark Angels instead.
I was thinking after the assault on The Rock, the Dark Mech fled with captured, wounded Marines and ran experiments to convert them into servitor soldiers.
Any opinions or advice from a lore or kitbashing perspective on how to go about it?
I'm having difficulty conveying that sense of surgical tech-conversion and enslavement, since even basic Marines are so modified. I'm also having trouble deciding how recognizable they should be as Dark Angels. Is putting Skitarii heads on Space Marines too dumb?