Zaxwerks hasn’t worked with FCP or Motion for a veeeeery long time. FCP 7 and M5 is where it ended. mObject is, as I noted, your only decent option. I haven’t checked, but I wouldn’t be surprised if one of their model packs didn’t in fact have an anvil in it. Otherwise, aside from being able to import vector files to extrude, you can import any given .obj you can find on the net, where there’s sure to be a plethora of anvil’s to choose from.
And I don’t know Stephen’s training, but I can’t imagine that there’s anything that Mark’s Motion 5 training over at Ripple Training doesn’t cover. The best and most comprehensive I know of in the english language.