Glove box lock

[bhap]

I have a 62 C10 with original keys - 1 key fits the doors, ignition and glovebox. I took truck out for a ride today and when I tried to open the glovebox, the button will not go in. Tried turning the key from horizontal to vertical in the lock and same thing - button will not go in. I don’t remember if I locked it last time I closed it or not, but this is the first time the button will not budge. Are there any tricks to getting the button to open? Does anyone know if vertical or horizontal is “unlocked”? I’ll sacrifice the glovebox liner if I have to - will latch push down to release with button jammed? Can new locks be matched to an original key?

Thanks for your help!