Happy to oblige BTW, Breitling were partners in there too with the Cal 11s. Oh, that photo was last year, wearing a Zodiac (née Heuer) today.
Here is some nice manual for all of you owning this beauty (and for other interested technology lovers as well): https://www.sinn.de/de/Download/Bedienungsanleitung/deut/Sinn_B_903.pdf
My daughter wearing her newly-arrived Citizen Kinder Time from 1968 which the company made to help kids tell the time.