4+ ward vs shooting for the crew (anvil can't be targeted, I think) and according to the FAQ a 6+ ward in combat. Oddly enough also T10, so the anvil can be targetted? Nowhere does it say 'runic spells' in neither the book nor the FAQ. The way I understood it it either buffs (not a spell!) or get to use magic shooting. There's nothing magical about the anvil other than the fact a drunken dwarf smith can beat it and stuff happens. Cheers!
the anvil works like a war machine now, much like the casket of souls, it has 5 wounds and T10, when the last wound is removed it is destroyed, so skinks will bea problem with 5 wounds and a 4+ ward
The best thing to take them out is probably a characteristic test, like an initiative test. Downside is that you need to get a spell like that off first. Dwarves tend to dispell most of my stuff lol. Gogo cupped IF and hope you kill the anvil (and some other dwarves/warmachines with it).