There is a fellow selling his FS400 here on RCU:
http://www.rcuniverse.com/market/item.cfm?itemId=914059
Two things I find intriguing.
1) He lists it as a "Series 3". Okay, anyone else know what makes a Series 3 versus any other series?
2) His manual calls the engine a "400-5R". This is of note, because all previous manuals including mine as well as other literature, test reviews, etc. it is titled as a "400-AR".