-http://www.klockit.com/

-All you gotta do is get yerself a cuckoo bird, stuff him in a box and...

-Found a company in England that sell a Cuckoo Clock Plan. I have not actual seen the plan yet, but it is on order.

Hope this is of use to you.

http://www.craftdesigns.freeserve.co.uk/clocksviennas.html

-You could try http://www.hubertherrclocks.com/ http://www.jmcw.com/quartz_cuckoo_clocks.htm

Also, take a look at http://www.brendlers.net/oldtools/cuckoo/ for some ideas from someone who built one.