Hi all, hoping for a little guidance. Anewbie to the forum but a little bit of experiencing tinkering with time pieces

I've just got my hands on this Sideral which seems to be running well.

Only problem is I can't seem to change the time.

The crown appears to have a first position away from the case but when wound it still appears to be loading the spring rather than moving the hands.

On a further pull the stem removes (a little too easily) as i would expect to remove the movement…

Tissot Sideral Vintage – can't set time