Here is a great previous thread on these pencils in case you haven’t seen it already: https://forum.knockology.com/t/the-rotring-tikky/2048
Patrick’s video is a must view and covers all the variations. If I am not mistaken, the Tikky double push version you pictured above is legit as these metal bodied versions did not have body markings but those were added on the 400. I recently added black, silver, and red versions to my collection and they all look like the one above.
Here is a direct link to the video on the Tikky lineage - the 7 minute mark is where you can see the details about the metal double push (but the entire video is excellent): https://www.youtube.com/watch?v=VblKtk8k9uE&t=461s
Hope this helps.
Cheers,
Tim