Glad you liked it! The buttons in the Null 2 STLs should fit both Nulls. https://1drv.ms/u/s!AqMvwiYIMMtmuxPdQUkjy_zNo4ny The files are called "Null2 Dpad Click V1.STL" and "Null2 Face Buttons Click V1.STL" Shoot me a message on here if you need anything else.
The PCB is very well made. The documentation is simply perfect and explains thoroughly what you need to do. There is also a video on Youtube that follows the seller's documentation. This is a pretty good project for soldering beginners - plus you get a handheld emulator with pretty great form factor.
As for the lack of audio, I have found a variety of solutions online to connect bluetooth headphones to the pi - which seem pretty easy (I haven't had the time to try them). I've also seen a few videos that show how to connect a headphone jack, but you might need to print a bigger case.
The seller is also very communicative and helpful. He usually responds within a few hours.
All in all, great package for a pretty good price.
One of the most fun DIY projects I've ever done. Ampersand's documentation and willingness to help troubleshoot on the product Discord helped get the project working properly. I am not a soldering expert by any means, but I strongly recommend getting a practice kit before tackling this. All in all I would definitely do this project again.