You need to tell us more.  What is the doo-dad you are trying to texture?
Has it been UV mapped?  If so does the texture you are trying to apply
correspond to the UV map coordinates of your "doo-dad"?
For example trying to put a Victoria 3 texture on Victoria 2 comes
out a mess because they have different UV coordinates.
You may need to get a template of your "doo-dad" and use
a paint program like Photoshop to make your texture fit.