What are they?13mm angle retainer strips
No idea on plastic,it’s hitachi. Strips of angle steel.What are they?
What plastic is the drill body? Some plastics are not great at being glued.
For most tasks, the basic poundland epoxy is decent enough. Used them many many times.
I did buy several tubes of fancy expensive epoxy but one leaked everywhere and the other went off before I could start it, so it was about £20 wasted.