Can we have a delete button for periods that DON'T have URIs yet?

[atomrab]

I know that we don't want to make it possible for people to delete periods from existing authorities without a really, really good reason. But if we could make a delete button for periods that do not yet have URIs, that would really help with workflow -- I've been working on the Priestley material, and in several cases I accidentally duplicated periods and couldn't delete (the workaround is to make yet another collection and import everything except the duplicate, but it's a pain). So, maybe it would be ok to delete pre-merge period definitions in a local IDB?