Had a similar thing happen about seven years ago with a couple guns......before I had kids and a fancy gun cabinet. Had two not fancy but decent muzzleloader mysteriously come up missing after we Had some sheetrockers completing work on my basement. Of course I am at fault for simply placing them in gun bags under the bed in the spare bedroom ( which was also in the basement) they were out of sight and out of my mind until a few months later when I wanted to go sight them in.....well needless to say, never saw them again however once a year I do get a call from the State Police asking if they are still missing. Lesson learned.