Yeah I thought so too, 99% sure you should only be able to change the gas piston not the other thing???
I'm pretty sure these come with the spring and guide if this is a complete kit? Confusing.
I know W&S sell a steel bolt set but that's just the bolt and nothing else that comes with that...
Best bit is though, these aren't rare... You can legit buy them from Asian retailers for cheaper even with shipping!!
https://www.milspecsolutions.co.uk/W-S-Airsoft-GHK-AK-Steel-Bolt-Kit-Type-1.html
You are indeed correct, I'm wondering when this was originally bought now