Hello! I have a huge problem in Fallout 3 The Pitt!!! (possible non-insane spoilers about collecting steel for the pitt:)

I read that in order to get the Perforator you need to collect 90 steel ingots. I collected the first 10 and turned them in, and now I am trying to collect 80 more to get the Perforator (to have 90) BUT, I am kinda trying to get all the trophies in this game, so heres my problem:::

Whenever I collected my first 10, I actually had 11, and I didn't know about the achievement, so I dropped that one in Everett's office.... It's gone... Am I screwed to get the trophy because now I can only get up to 99 total? I'm pretty sure I can still get the gun, because you need 90 and I turned in the 10 and I can still get 80, so that's awesome... But I don't think I can get the trophy.

If anyone else had this problem let me know if you could fix it or whatever! (or if you think I can't get the Perforator or something)

Thanks!