Guards Badge.

[88d]

I don't think its a year number as this one would be before North Korea was founded, As for the solder I think its a repair done by the owner as I had to remove a little to see the number properly so it was done after it was scratched in by who i'm guessing it was issued to, It would be interesting to find out what the numbers indicate as they seem too low to be a mass issue thing so perhaps they are for the surviving members like you posted earlier. Maybe the only way to find out currently would be to ask a defector in the south or possibly it may be in a Soviet report on the KPA in a similar manor to how the US would have reports on the ROK army structure.

[CtahhR]

If you look through the rest, so much solder. They can't all be done at home, where would they get the solder from?

[88d]

I would guess even in North Korea they have local repair shops or individuals for fixing minor things on the communes instead of sending fixable items back to the central factory for minor jobs which may explain the sloppy to passable workmanship on the couple we have pictures of depending on the workman on duty that day, However the solder on mine was very soft so it could possibly be a home/Barracks fix with a bit of scrap lead found by the owner.
As for the amount of horrible soldering maybe the factory was using too little or a poor quality of solder on them during production and wear and tear over the years caused the majority of them to break resulting in the rustic reverses we see now but as with most things DPRK we will probably never know until after it collapses and even then its a long shot as to there being any information coming up.