That picture you posted is probably a "cartridge" replacement for the rubber that's molded in. It should have rubber in it and a sleeve around the bolt. The outer sleeve is probably designed to press into the housing after you burn out the old rubber. The old stuff isn't going to press out without it being softened a bunch, so just tossing it in a fire is the easiest way. It won't get hot enough to hurt the metal housing.
The other option is to send the whole thing in to get revulcanized (Steele does that
Link) but it's twice as expensive as what you found at Chevy's of the 40's.
Like I mentioned, casting a new bushing out of polyurethane is another option if you want to tackle that.
This is what I used, but it looks like it's out of stock currently.
