Well, I couldn't get SFM to work, but I used the in-game preview instead and that works. Thanks

I did this, and the model shows up in SFM. However it comes up as untextured with the black/purple pattern, even though I also copy-pasted the textures aswell...

I put the hat model files from the zip to:
Steam\SteamApps\common\SourceFilmmaker\game\tf\models\player\items\engineer

and the textures from the zip to:
Steam\SteamApps\common\SourceFilmmaker\game\tf\materials\models\player\items\engineer

Did I put something in the wrong place or am I missing something? I'm kinda lost here.

I am at the step of submitting my hat, and it requires a preview image that is 512 x 512. How do I import my hat into SFM to make preview images for the workshop? I have the zip file that was created when verifying, but I don't know what to do with it for SFM.