Just in case you have forgotten about us P-J, I thought I'd give this thread a bump. Been three weeks since ur last post - I hope you haven't got bored already.
Might be helpful to set up a 1 level demo with multiplayer online to see how viable this would be whilst you're busy designing all the millions of old and new levels.
Did you get any further with your plan to find an artist? If not, why not zip a load of trees, bushes and signs together into the Zone so we can all have a go at the refurb?? (yes you'll get x10 types of new trees - some with twigs, some with snow and fairy lights, and also x100 new signs). Enthusiasm on EAB is always is always high; but you might need to keep proding potential contributors.