Sorry if I'm stating the obvious, but have you cast around and checked any nearby gullies or thickets?
I say this only because I had a seat disappear last year (cable cut through) and had given it up for lost until one day a few weeks later I took a different line on a stalk due to the wind coming from an unaccustomed quarter and found the seat more or less intact at the bottom of an overgrown gully less than 200 yards from where it was taken from.
I still don't know who took it, but they weren't scrap thieves or shooters, so my best guess is vandalism by antis.
Needless to say, no deer were shot, but I still went home happy. I hope you have similar luck with yours.