Rear door mechanism

I have a 1993 993cc Hijet. I can't get my key to turn in the rear door lock/button. My key is *slightly* bent. Is it likely that the tailgate has been replaced (i.e. lock from a different van) or just that the bent key can't turn in there?

I'm guessing the key got bent by somebody trying to force the lock.

Also, the tailgate door card is missing, and there doesn't seem to be any sort of interior handle. Should there be one? I can get it open by pulling down on the linkage but will try to fit a handle if there is one.

Never seen an interior handle on a tailgate. Either it's a different tailgate or a different lock or maybe it's just seized? Try some WD40 for a start. If you only have one key, get a copy fast before that one breaks - they're quite weak.