[email address])

I plan to eventually migrate the calendar to my own website,
publishing an iCal file, but don't want to lose the readers
subscribing through Gcal, or the gcal-published iCal and atom feeds.

So, what I'm asking is: is there a way to convert the gcal-managed
calendar into an external (imported, like the things that show up
under "Other Calendars") calendar, retaining the same ID (and thus,
URL's).

I know it's not possible in the interface, but perhaps someone at
Google could make the change manually?