If you want to test a tce extension and the associated dep file, it is better to boot with the codes "base norestore" and copy the extension, the associated dep file and all dependent extensions to a directory such as /tmp/test.
/tmp/test would then contain something like:
extensionA.tce [the one to test]
extensionA.tce.dep
extensionB.tce
extensionC.tce
...
Where extensionA.tce, extensionB.tce, etc are listed in extensionA.tce.dep
Then try "tce-load /tmp/test/extensionA.tce" and if everything works, you're good to go.