For those who've asked, here's some pics of the new ride. The spears are stick on with the black rubber center. I was able to get in touch with the previous owner who swears the car had spears when purchased. My guess is that when the car was repainted the originals (if there really were any) were trashed and the paint shop went cheap and used the aftermarket ones. It's got a decent paint job on it now but I'll probably have it painted in a year or two. It's wearing the original color Code L Medium Teal Blue Mist.
If your car was built in Canada, you can get all the info you need. If not, well, then you can't. If your VIN has an "I" in it, it was built at the Oshawa, Ontario plant. GM of Canada will have all the records.
Thanks Ken. My car was built in Flint. I just received a '68 parts manual and the spears are not listed for a GS400. Previous owner (son of original owner) still swears that's how the car was when new. Maybe the dealer had original style spears on the car or it was added at some point by the original owner. I guess I'll never know for sure. I happen to like them so they'll stay on at least until the car gets repainted a few years from now.