I've been thinking about tidying the map up a bit, but due to the size of it this is quite a big task

Instead what I thought about doing was leaving the current map "as-is" so people can update it just like they can now, but also providing a "cleaned-up", read-only version if people only want to browse it.
This is actually quite a bit easier (I think) as I can grab all the data from the first map, remove any old entries, make sure everything has proper names and the right symbol, sort in into alphabetical order, etc. then make that available for people to view in Google Maps and/or Earth. Unfortunately what I can't do (as far as I can tell) is make that new map updatable, but provided I repeat the process every couple of weeks or so to pick up changes I think that should be OK.
What does everyone else think?
Cheers,
Paul.