Here is a link:
http://www.machinistblog.com/bogstandards-paddleduck-engine-plans/If you log into HMEM there are build logs and lots of info and tips available as well:
http://www.homemodelenginemachinist.com/You will need a mill as well as a lathe, although having said that, you may be able to do it all on a lathe if you have milling gear for it.
I only have small stuff, taig (peatol) lathe and seig x2 mill, but both these managed all the machining with capacity to spare.
Good luck, and pics are required.
If you think I can help, get in touch., although the deisigner, John Moore aka Bogstandard is very approachable and helpful.
Peter, yes they are a pair of Boggies and were the first major engine build I attempted.
Ian