I used a glass cookie jar for my vac chamber as seen in the first page Shaun but a steel ice bucket would work as well for the chamber. Or even a big mason or pickle jar.
I put that tusk in mineral oil in the vac chamber to pull the oil in without ill effect.
Might help save that brittle bone if you can get some oil in there for sure.
I've played with some bone in my vacuum chamber and I was amazed at how much stabilzer solution was pulled in.