That does not look like something weaver would do. I do not have any Weaver locos with DCC however. ON the other hand that particular model was done in China I think, and might be similar to DCC installs done for other importers if it were factory. But that looks like someone did their own install.
I have some SoundTraxx decoders that are wrapped in the same Shrinkwrap color. These are older model soundtraxx but to my ear quite good sound. Mine have no marking either but one is still sealed in the original Soundtraxx package. These would be models before the Tsunami and Econami series they are selling now.
If it were me, I would try to salvage the decoder, That might be two decoders - one a sound oonly and one for motor control. IF the motor one is not working, you could use the sound one and just put an NCE D408SR in for motor and lights.
The fact that it ran and had sound means it might still be alive. I would clean up the wiring and check it all out to avoid shorts and what not.
