Ah yes, just some weapon models made by Timothy Hsu on Sketchfab.
With a bonus utility case model as well.

Well it's been a while since the last time I ported stuff, so I thought maybe it's time to try port some more.👌
It's also the first time I'm using the PBR Material Converter tool made by Mushroom Guy, the same one used on the Modern Warfare 2019 SWEP Packs, which you can find it here:
https://github.com/mushroom-guy/mwb-materials

It's quite simple, navigate to where you have the textures for your gun. If the Roughness, Metalness and AO map aren't separate, use a tool like GameImageUtil to split them up.

Now rename the textures like so:
nameofyourgun_rgb for Albedo/Color
nameofyourgun_r or nameofyourgun_g for Roughness map or Glossy map
nameofyourgun_alpha for Metalness map
nameofyourgun_o for AO map
nameofyourgun_n for Normal map

Start the tool. The standard settings are good enough, so we won't change them. Click on "Open Folder(s)" and find the folder where your textures are. Make sure that the folder structure where your textures are located don't have any spaces, or the tool won't know where to put the finished .vtf files. Select the folder and wait. After the tool is done, you should have a folder called output with .vtf's inside of them or where your folder structure as the texture finish export to VTF(If you check Move output to VMT path). You might need to rename the .vtf's, as they use the folder name where they were located in instead of the texture name. Open the .vmt file, also located in output(If you enable.

Then add the $cdmaterials path to $basetexture, $bumpmap and $phongexponenttexture.
So "$basetexture" "\galilsar_rgb" becomes "$basetexture" "models\weapons\rtx\galil\galilsar_rgb" for example.

After that, just basically put them onto the materials folder of your model, and that's it.👌

Be reminded that apparently Source (or just SFM) cannot load a normal map that the size is bigger than 50 MB, otherwise it would just appear as checkered texture like missing textures. If it happens, then I suggest you to export the vtf file into something like a png, then import it back as a .vtf file, you might lose some details because of this, but it can greatly decrease the size of the texture, making it usable in Source.

Currently includes:

• StG 45(M) / Gerät 06H / MP 45(M)
• Viet Cong Homemade SMG
• Prussian Blücher Sabre
• Utility Case (Bonus)

Includes:
sketchfab\timothyhsu\prussian_blucher_sabre\skf_timothyhsu_prussian_blucher_sabre.mdl
sketchfab\timothyhsu\stg_45\skf_timothyhsu_stg_45.mdl
sketchfab\timothyhsu\stg_45\skf_timothyhsu_stg_45_magazine.mdl
sketchfab\timothyhsu\utility_case\skf_timothyhsu_utility_case.mdl
sketchfab\timothyhsu\viet_cong_homemade_smg\skf_timothyhsu_viet_cong_homemade_smg.mdl
sketchfab\timothyhsu\viet_cong_homemade_smg\skf_timothyhsu_viet_cong_homemade_smg_magazine.mdl

Credits :
Timothy Hsu - Original creator of the model.
Mushroom Guy - PBR Material Converter Tool.
NeoLin - Porting to Source.