I guess it would depend on what it is, what its doing, whats been added and whats deleted.
When you say a "custom build"... you mean its been rooted and heavily altered or something else? (I didn't know you could root AW)
Moto is supposed to be deploying 2.0 some time soon. 2.0 is significantly different than 1.5. Mine doesn't have it yet, but you could be looking at 2.0. What happens when you factory reset it? That should wipe it clean back to the factory install.