Half the vehicles I get in don't even have spare tires, let alone carriers or locks for them. I don't see the point of locking the spare, the lock on my 2010 Silverado got thrown into the weeds the first time I needed the spare...took me longer to get the lock apart than it did to change the tire. Plus... most of the time I see half worn out tires on crusty steel wheels being used as spares. Nobody is going to steal that.
Tailgate theft is a pretty big deal. I doubt someone would steal a tailgate from an old Ranger but anything can happen. It was (probably still is) pretty common for Super Duty owners to lose theirs... big market for that, beat up work trucks are always in need of a good tailgate. I take the tailgate off mine every time I haul gravel or load my camper...it's much easier to unload gravel, much easier to load the camper with it out of the way.