I can only answer your second question, as I haven't done my own tattooing.
Yes, the ink lasts for a long time. Like all tattoos it does fade slightly, but can still be readable many years later, at least that's the case with my goats. I have two almost 9 year old NDs that were tattooed as...
I know this is an old post, but it's pinned to BYH's home screen.
I'm not an expert, but the conformation looks more like that of a pygmy rather than a Nigerian Dwarf, especially the head. Maybe some kind of pygmy cross?