The first problem I notice right away is that while there’s an ARM5 chip inside the MBWE, there is was no ARM port for Gentoo. Normally you would install portage from a stage3 or compiled tarball. However that isn’t going to work. In order to make Gentoo function on the mybook I’m going to have to work from the stage 1 or 2 tarball which is just sources.

Note that there are some useful conversations here and then here (the best link) in the Gentoo forums on converting other Linux distributions to Gentoo. The flaw in the procedure however is that there is no ARM port of portage.
Problem solved!