Got it. In that case, if you're just looking for a solution, you could always just extract the DOL from the HBC WAD (available via ModMii) and write that over the custom forwarder's DOL using CustomizeMii. That way you would know that your DOL is good.
Alternatively, you could:
- Grab the HBC WAD via ModMii
- Use CustomizeMii to extract the sound, images, brlyt, and brlan from the custom forwarder that you downloaded
- Add those to the HBC WAD and install
...but that's effectively just more work to accomplish the same thing.
Obviously make sure you have a backup before doing any installs, but everything you'd be changing would be effectively cosmetic.