Harddrive Replacement, missing screws, how to?

hey, I got a Mac Mini Server from Mid 2010 (A1347) who is completely dismantled. My uncle gave it to me, his IT spec took the Harddrives for Backup because the Mac Server is supposed to be broken. I have some spare time and wanna check this. But now how I got it, its just a big mess of parts and after going through ur Mac Mini 2010 HDD Replacement Howto I also figured out some screws are definatly missing here. I could follow along till the part with the HDD itself. In the server laying 2 HDD and some sort of a mount for those. Id like to know how to get all back together for first and if I can get those missing screws anywhere in germany for cheap? Dont wanna spend too much money to figure out that the server is rly broken...

so far...