Introduction and 71 Suburban Tailgate Lock/Latch Query

[NZBurb]

Hi everyone.

By way of introduction I live in New Zealand and was recently fortunate enough to stumble upon a 1971 K20 GMC Suburban in Arizona. Six months later she's finally arrived and is working her way through the local certification process - I'll be sure to post some photos shortly!

I have a quick query which is actually a bit hard to explain without a photo (she's currently at the mechanic) but thought I would give it a crack in the interim. I have a push-button lock on the tailgate - when it's set to unlock the pin coming out of the lock lines up with a hole in the internal latch in the centre of the door - the latch then naturally doesn't engage to release the top door. I've pulled her apart, lined her back up so she works, but when I lock and then unlock the pin ends up aligned to this damn hole. It's hard to tell if part of the latch has broken away previously to cause the problem or if its an issue with the lock/pin. If anyone has any tips or photos of their tailgate latch lying around, or know of a supplier who stocks (I've tried LMC and classicparts) I'd love to hear from you!

Thanks in advance for your help guys - really looking forward to working my way through all of the great info and advice on here.