I just have extra springs, because it was minimum size of the order. And I think that somebody needs in it. It will be greate, if you compensate the prime cost of the spring (I can show you invoice). I will not have extra PCB. If you want, I can organize the production of any parts, but it will be extra job for me, and I will ask some payment for this service. All prices, that I wrote, is prime cost without any profit.
I try to select common parts, that you can buy at Aliexpress. I have ordered PCB at jlcpcb.com. They can also assembled this PCB. Maybe it possible, to share the order information of this PCB on this site.
Also, when I test the stepper PCB, I will make Raspberry shild and PCB with socets. Of course all files will be open source.