Setting A Custom Head For Mars City

I'm wondering if anyone knows a way to change the head that is loaded for the player on mars_city1 as I have given the doomguy back his helmet and it's basically finished except for this map which is before he gets his equipment so in this case he should not be wearing the helmet. Changing def_head to head_player_helmet for the player.def affects all maps since they all inherit head_player from here, but mars_city1 uses a different unarmored marine body so I'm wondering if I could also set a custom head for this map (changing "inherit head_player to something else.)

You know, I've recently discovered that Sikkmod allows you to wear a helmet. And, as far as I can tell, it works properly. You'll get it only when you'll receive your armor at the Underground Security. The only downside is that the helmet has a little bit of a lighter tone than your armor. In that regard the alpha helmet would be better, as it has a matching green tone.

P.S. Apparently, the helmet doesn't show up in cutscenes. Bummer.

They should've used the helmet from RoE.