Did I totally fuck up? (I Could Make You Care spoilers)

Hey, I'm trying to do Veronica's buddy quest a little late in the game, and I'm at the point where I have to find the new Technology. The problem is that I might have wasted all three choices. I've already completed Helios I and not in the Super Death Ray fashion, I've done Vault 22, and although I made sure Keely didn't destroy the data, I did turn it in to NCR, And I'm afraid that I might've sold the Pulse Gun from Vault 34 wayyyyyyyy back before I knew it was anything other than an icky energy weapon. The Wikia says the Silver Rush sells the Pulse gun, but mine doesn't (lv 23)

Any Advice?