Grimey Injectors

[MJ80]

Pulled the injectors out this morning to get them cleaned and tested in desperate attempt to get mobile again.
I don’t know if this is normal or if I should get looking at the pump. The ends of the injectors are all black and two of them were quite gritty. I ran the grit over a magnet and it stuck.
One of the injectors was missing the copper seal at the bottom and the shaft looks really worn around that area.
I haven’t had anything magnetic out the fuel filter when it was drained.
Any ideas what it could be?