+1 on all the positive comments.
I currently have 3 680 series guns.
The only failures I've seen on 680 series guns have been three differet cases of broken hammers.
One of them was my trap 682, a 1985 production gun.  It fired quite a few shells before the failure.  The hammer simply fractured into two pieces.
The good news is that Cole's sent me a hammer and it simply dropped in without much fuss or disassembly.  Just drive the axle out with a pin, and presto -  new hammer.
I'd take a spare set of hammers to Argentina.