My 2008 Subaru Outback Sport has been involved in a wreck and likely needs to be totalled. CarFax does not show a transmission or engine replacement but I bought it having been told one was replaced. The VIN is  4S4BP61C287310455. I think I found the transmission sticker itself so the first thing is "is this the transmission tag". I have attached the sticker. I have spent many hours trying to decode and just overwhelmed. There wasa another similar sticker about two inches away with no writing left that I can see..

I am trying to prove this is a replacement from the original transmission. I am going to go back tomorrow to the salvage yard and look on the passenger side door and just trying to do everything I can to prove this. Does anyone have any advice? 

Yep, Subaru shows 879996 as the Transmission serial and 424274 for the engine (IIRC stamped into the engine block next to the starter).