If you find the fic below please look back at that post (ignore the comments - while they're excellent stories they weren't the ones I was looking for.
A fic where Tony tries to kill Bucky thanks to previous knowledge of the video which captures his parents death but is stopped at the last minute by JARVIS, (Steve? And the others) who realizes that the man is not Bucky but is actually wearing a mask like the one Zemo wore. Steve and Bucky are together in this fic.
Thanks in advance