Ported Mesh Problems

So, I’ve been working on this model of a NCR ranger with a custom texture and ported meshes that I added to the mesh. The problem is that the ported meshes added were all messed up when I started Garry’s Mod.

To give a basic understanding, it’s supposed to look like this:
Imgur

But in Garry’s Mod, it looks like this:
Imgur

Is there something that I’m doing wrong? I’ve merged the mesh with the skeleton and weight painted it. But it had no effect.

By all means it should work, can you give the QC for the code? Also should look into remaking it, maybe something happened, try moving the character around in blender to see if there’s really no error in the weight paint.