The Quorn is a seriously fun project, I've thoroughly enjoyed my build. A challenge but that's why it's so rewarding.
Hemingway have been great supplying replacement castings. Mine is based on MK2 castings I bought from eBay (bought by somebody and never started), so was lacking some of the ali guard castings and suchlike. I also had trouble with the gunmetal pivot casting, party due to my momentary stupidity, but mainly because of a huge void inside it. The chap at Hemingway was more than happy to help, even though they didn't supply me a kit, and took an order over the phone for the bits I needed.
Please do start a build thread! I need to update mine once I've finished filling and painting the various bits prior to assembly.