Good idea....
Here's a couple of Q'
1. Are you thinking of barn size, blocks? maybe with the instructions on how to put together that block at the stop.
2. Would they be good with keeping it up for the 3 months or maybe just on weekends.
3. Willing to work with the shop hop ad's to promote this and help explain whats going on? or a few of the shops near your town to help pass out flyers?
Think it's a Great Idea and a good way to promote local merchants. Good Luck!!