Thanks, Raul. There are several 308SXs for sale, on eBay and elsewhere. In most cases they do have an original SAEC headshell, but it is not the ceramic one. Don't know whether or not that means the headshell is not original to the tonearm. (I think I did see one for sale in Hong kong that does have the ceramic headshell.)
My major reason for being interested in the SAEC has to do with the fact that with my L07D turntable I received an accessory OEM Kenwood arm board that bolts to the rear of the chassis to allow one to mount a second tonearm. This is really nicely made, heavy, and seems to have been cut for the SAEC 308 specifically. Looks like it will accept either the 308N or the 308SX. But it will not accept the 407 or 506, based on my examination of photos. (Kenwood made at least four different arm boards for the rear of the L07D chassis; each one is dedicated to a different vintage tonearm. Wonder whether they made one for Lustre.) I readily concede the the Lustre may be superior, because I certainly have no basis to argue. On the other hand, I am not inclined right now to spend about $1100 to buy the 308SX. That decision will have to wait a bit while I sell other stuff.