I realize you don't want any other tweaks to makeup and such, but this version is still pretty close to the original, but with no scar. Link.
I've seen that mod and it's really nice. After getting used to Cassandra without the lipstick the makeup it feels jarring. I know I'm being overly picky and silly. If she doesn't have a scar why shouldn't she be out kicking butt with make up? She can of course. She's Cassandra. She does what she wants, but that one didn't quite do it for me.
Sunegami wrote:If you can find it, there's a great mod that lets you heal Cassandra's scars over the course of the game; you can use that to remove her scars from the get-go. :3 I believe it was called "Scars are Healing"?
EDIT: my mod directory has it saved as "Cassandra Healing Variants by Zalunya".
I'm not sure if it's still floating around, I don't want to post my copy just in case it is.
There's a Zalunya on Nexus but if it's the same person, it looks like all their mods have been removed by the author. There's some modders I've bumped into across the web who have moved their material to other places like Wordpress and even Tumblr. I'll look around and hope that they may have moved rather than left the community entirely. I think I remember that one but I didn't download it when I had the chance, unfortunately.
Edit: I'm looking into doing this myself. Someone was kind enough to share a number of tutorials but I'm as raw of a beginner that there can be. At the moment I can't open the Mod Creator at all because I'm getting the error about the Official Patch being deleted. I went through troubleshooting steps to run as the Admin and reconfigure. I didn't manually delete it that I'm aware of, but my game has been modded heavily so it's entirely possible I messed with something that's causing a problem. I'm going to install a clean copy of DAI on another drive and start from scratch to see if I can even find Cassandra's files. I have a vague idea of what I'm looking for by looking at the old Origins mods. Very vague. Like I said, I'm still pretty pathetic at this stage but I'm trying to learn. Everyone starts somewhere, so I'm willing to see where it goes if nobody wants to spend time on such a picky thing like Cassandra's scar (which probably isn't especially easy to do.)