I have managed to install the old 32-bit virtualboxes somewhere else. This, plus an Ubuntu, and a couple of other Linux boxes are now up and running the standard builds and tests every night.
My OSX box is dead and needs a new hard disk, but since my laptop runs the same OS, this means that this platform is covered.
So the last two bits would be the Windows ports and Solaris/sparc. I will just concentrate on the first three and forget about the last one for the moment. Hopefully we will have all the platforms tested and a new release before I fly to Boston for the APS March Meeting.