Screwed up hidden action

So, as the title implied, I screwed up the hidden action in Valentine (getting the Schofield Revolver in the doctor's backroom). I was stupid and entered without checking on my guns, so I went in with one pistol which was dry on ammo and nothing else - obviously I got ass-blasted, and now my question is do I have another chance to do this hidden action? I am well aware of the fact that I can get the Schofield through other means but I'd really like to do it this way