Vetta was more of a late 80s and early 90s thing. I am pretty sure it could not be original. Palo Altos were sold as frames anyway, IIRC. Oh, and Palo Alto owned Avocet, more or less.
400g wasn't untypical for saddles of the time. I agree if the Vetta is 213g, it must have aluminum rails. Aluminum rail saddles break. I remember a friend of mine breaking a Mod III like 40 miles from home on a ride. Funny, to me...
The Avocet Mod I was the entry level saddle with the thickest padding. Supposedly aimed at beginners and intermediates. Mod II was their standard racing saddle. Firmer and I believe a touch lighter. Mod III was the same but with aluminum rails. Top model was the Avocet RS, which was a rebranded Sella Italia RS, a precursor to the Turbo and very similar.
At some point in the early 80s, all of the Avocet saddles kept the same model names, but they changed. My recollection of this period is a bit vague. Most were rebadged Turbos, more or less.
That may be more than anyone wanted to know about Avocet. For some reason they seem to be largely forgotten. At one time they really did loom large. Almost everyone rode Avocet saddles.