If you are unsure, always go the easy fix route, that would be E6000.
Once confident, Zap a gap will save time, but is an absolute bugger, to try and pull apart as I am figuring, you have found out.
The AbS weld on not too sure about, perhaps it is in the name. It may partially melt the ABS to form a permanent bond.
I'd go with the E6000 you just need patience while it is bonding as it will take 24 hrs to set.