How can I find my steam activation code?

I bought the game back when it was doing the daily sale’s where it reduced in price over 24 hours, I bought it for myself, used my code, I’m on steam and all sorted out
However, I also bought it for my friend who wasn’t playing rust much at the time, now he wants to but we realised how much rust has moved on, we can’t seem to find his steam rust code,
Is there a way I can find this? I can’t even remember how I received mine at the time because I was quite in touch with rust updates it just passed me by simply, now it seems to be an impossible task
Anyone able to help me? Thanks

Edit- I found my email receipts, both of them, so I have both original codes etc, I’m still trying to see if I’m missing something

Source: Section rules. READ OR GET BANNED. Want to advertise/discuss a server or ask why/if one’s down? Use the RUST SERVERS SUBFORUM.

It’s the sticky at the top of this exact forum.

Oh, ok thanks I feel stupid for not looking, (I am) I’m trying to remember the email address etc now, my bad stuffing the forum with my crap :x

it’s all sorted now, yeah… sorry about that :confused: thanks for the help though it sped it along by a lot seeing as I was looking in all the wrong places