These are NORMAL London citizens...
(Concept/experimental art and designs)

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These are NORMAL London citizens...
(Concept/experimental art and designs)
“There are no happy endings in real life, Sal. We all get the same terrible ending…death.”
Sal's face
I want to start this off by saying I have no knowledge on how wounds really work, this is me just spitballing stuff that sounds realistic enough.
I'm not trying to call out any fanartists! Continue to draw him like you want to! I just want to mention what I believe is the most accurate representation of Sal's face, from my own perspective.
Canonly, Sal's face underneath the mask would have to be insanely mutilated. He wouldn't need a whole prosthetic face if his original face just had a few ugly scars. Considering all the shit he's gotten for it, this is definitely something he NEEDS to wear, not wants to. His original top layer of skin got too messed up that he needed a new one to keep that skin from being as vulnerable.
(More gore-y description of his possible face- skip it if you'd like!!)
Maybe his original face had so many chunks taken out of it that it couldn't heal back properly, thus leaving too many open vulnerable areas even once healed. Maybe enough of that top layer of skin was taken off that what remained was too raw, even when healed, to not have an extra layer of protection put over it. It's whatever you can think of- but realistically, it'd have to be enough to need a prosthetic.
(End of gore-y description)
But as for drawing him without a terribly messed up face- I get it. It's easier, and less gorey, to draw some scars that dont mess with the anatomy of his face. That, and there's many characters out there who wear masks who dont need to- and coming from a fandom with one of those characters, some may forget that Sal's mask isnt exactly a choice more than a need. Of course, he's made it his own personal trade mark by now with it. He's more confident. But there had to have been a time when he was younger and he HATED the mask. Why keep something on that he got bullied for all the time? Because his face underneath is, for lack of better word, "scarier" than his prosthetic face is.
Either that, or he was convinced that his face beneath the mask is worse than the prosthetic face is, when in reality it isnt. But seeing the snippets of his face (specifically in the last episode)- I think it's safe to say that his original face IS fairly scared enough for a prosthetic to make sense.
Either way, how you draw him is justified! But I think there's proof that, if we should get an up-close shot of his face, it'll be quite mutilated- even after being healed.
Faces of World War I Sculptors and artists designed lifelike masks for gravely wounded soldiers. Anna Coleman Ladd Archives of American Art
Idk why but this is hilar to me