Mario Galaxy 1 .bdl files missing

[KartingKoopa]

So about 2 months ago I decompiled Super Mario Galaxy 1 using the latest version of Dolphin Emulator.
The filesystem however, completely lacks .bdl files. I should also mention that my copy of Galaxy 1 is in .nkit.iso form, maybe that's important... 
What should I do to get my hands on these .bdl files?

In the comment section of the Mario Galaxy page you'll be able to find when the problem arose:
(https://www.models-resource.com/wii/supermariogalaxy/)

[Koopa512]

.nkit.iso means it's converted from NKit, get a new dump of the game using native ISO, WBFS or RVZ
and .bdl files are in .szs archives

[KartingKoopa]

.nkit.iso means it's converted from NKit, get a new dump of the game using native ISO, WBFS or RVZ
and .bdl files are in .szs archives

Thank you for the reply!
Would converting the .nkit.iso that I have back into an .iso also work? And could you elaborate on what those .szs files are in relation to .bdl's?
Again, thank you for the help, I did not expect an answer after so long

Edit: Nevermind, figured it out! By the way, Galaxy uses .arc files, not .szs for anyone reading this in the future

[Koopa512]

.nkit.iso means it's converted from NKit, get a new dump of the game using native ISO, WBFS or RVZ
and .bdl files are in .szs archives

Thank you for the reply!
Would converting the .nkit.iso that I have back into an .iso also work? And could you elaborate on what those .szs files are in relation to .bdl's?
Again, thank you for the help, I did not expect an answer after so long

Edit: Nevermind, figured it out! By the way, Galaxy uses .arc files, not .szs for anyone reading this in the future

Thanks for the correction