Yes Kaboom, if you use a model and rename it you will have to upload that model with your level, plus any skin files it needs. There are instructions in the readme file (I sometimes wonder if they ever get read).
I only name the models model#.3ds if there are up to four in the folder, if there are more I name them according to what they are and leave it up to you to rename them.
You will have to upload a zip folder with the model that you used and the skin files in it, for people to use to see the model in your level.
