Set Iso on Vitomatic IIIB Ultron

Hi all, i've just received an awesome Voigtlander Vitomatic IIIB with Ultron

Evereything is working correctly but i don't know how to set the Iso..

I've found a manual online but is for the IIA (slightly different lens type)

Can anyone help?

Many of these Voigtlander and other rangefinder or even simpler viewfinder cameras with built in meters and leaf shutters set the ISO/ASA dial in the same way: press/flick it down the unlocking button at the base and set the dial with the red dot to the appropriate value.

This is one side with the DIN values. The button you see here should unlock the dial: http://www.udo-afalter.de/images/vitomaticiiibunterseite.jpg
This shows the ASA/ISO values: http://www.abload.de/img/dscn2225kxa4.jpg

Thank you Ricardo!