sasha, you are right, it seems its a 0.3p without the etching-didint know there were some out there like that, maybe its a prototype of some sort, but the 0.2p prototypes had prototype etching on the lense....
The prototypes had an etching and round orbitals. Could be this one is a sample, athlete exclusive, or just happened to miss the etching process. Just a guess on my part, though.
I have both kinds of prototypes....round and semicircular, obstructed view and clear...doesnt seem to matter. I believe there are different versions...and this is just another variation...minus the etching. They look sweet, nice find.
Some of the Zeros issued out to various athletes didnt have the etching from what I remember, so it looks like you have found quite a rare pair, well done mate.