In fact it's more than a Sideral, it's a Sideral S ! Water restistance is improved by using a seal between plexi and figerclass case. Sideral S have also a stop second feature which is not available for other models. And there is an antimagnetic shield inside the case if I'm remembering well. Original mesh is not the more confortable from my point of view.
The vintage watches have great dials. I recall that the first watch I was enamoured with was my uncles round tissot two timer. I thought it was the coolest thing ever - you could use the crown!