From: Hanford, CA, US
Hi-re your comment,about other updates overriding mods-Maybe its the Redux sound mod that is interfering with it? Peter.
As VPaulus said, the sound mod is not likely the problem. With the way you are manually modding the program, the only thing that would overwrite without you knowing would be the official game updates. I believe those overwrite all game files to the latest version, thereby undoing your work.
I downloaded the Elite Units mod and looked it over. It has only bigunit pics for the new units so if you just replaced the original bigunits folder with the modded one, you'd be missing a lot of pics. Actually, you'd be missing all the vanilla pics. But if you dragged all the Elite pics and dropped them into the vanilla bigunits folder, then you would be ok. So I'm not sure how none of the pics are showing up. I would expect to see at least the vanilla pics or the new elite pics but not both to be missing.
Last thing I can think of is to check your path. Starting with wherever your game is located, the path should look like this (because you're modding manually and not using GME):
Follow that path and look in the bigunits folder and see if all the pics are there. Best of luck
PS: Earlier you mentioned the Sea Lion campaign. I don't have that yet so I'm not sure what the file path would be for that. So if you're playing that, maybe there's another bigunit folder hiding somewhere?