If you still have the NAND keys and the boot2 system, you can restore that backup yourself.
You can start out with Softmod Any Wii guide. In chapter 1, part 1, under "Other desperate options", you have an option for "Boot2 Bootmii option". Grab that .zip file, extract it to the SD card, and do that process to launch hackmii installer and go through that installation.
Do part 2 to launch the hackmii installer, install HBC, reinstall bootmii as boot2 (just to be safe that it's there), then do the "prepare the SD card" option. This will copy the bootmii files to the SD card.
Before you do part 3, place the NAND backup files to the root of the SD card, then follow part 3 to launch bootmii, but instead of making the backup, choose to restore the backup that you already have.
Once that step is done, It probably won't hurt to finish the mod via chapter 2 to get your mod up to date, then when done, go through the bootmii process again and get another clean backup.