You have to check out this thread on The Jockey Journal, a guy named Mads in Copenhagen, Denmark is building an Excelsior Overhead Cam Super X almost from scratch.
He is machining a set of duplicate Koslow overhead cam heads from scratch. Not for the faint of heart. If this doesn't impress you consider that Mads built an Indian Four replica from scratch using a four cylinder car engine and shaft drive, just amazing !
See the build on Jockey Journal http://www.jockeyjournal.com/forum/showthread.php?t=70554&highlight=excelsior
