If you will give measurements, Closer pictures and different angles of it then you will probably get a better response from the guy's and gal's on this site.
Also you may want to post it on the whats it forum. cool looking item..................HH
Correct. It is the remains of a dogbone style radiator cap. Probably from the teens or 20's. I don't know why it says Shreveport but I found a small pic of a similar one that says Oldsmobile. For some reason Tnet won't let me post it.