Well, I finally managed to persuade Monotone to behave --- rebuilding the database only took about six hours... however, I'm now finding some odd problems that lead me to suspect that the v2 release wasn't built with the same version of OpenEmbedded that I've got.
Firstly, oe-amsdelta.diff doesn't apply, mostly because my version is referring to 'include' instead of 'require'. If I patch in the changes manually (changing to 'require'), the when I try to build bootstrap-image, I get:
| ERROR: Cannot satisfy the following dependencies for \ task-bootstrap-unionroot:
...and a long list of package names. Each package will build manually, but shouldn't this happen automatically? Plus, some of the packages referred to are missing, such as amsdelta-installer and sysvinit-pidof (there are no bitbake files for them in the repository that I can find).
What am I missing?