Agfa Isoly Focus help please

I have this Agfa Isoly that I recently purchased, it's all loaded and ready to go with 120 film, but I'm confused as to how the focus works.

The camera has a 'Achromat' lens and around the lens there is a silver bezel.

Stamped on the bezel there is a number 30 and three sets of two black lines.

On the barrel of the lens there is a white guide mark.

There is a D shape cut out in the silver bezel but I think that is because someone has cracked the bezel.

So anyway what I was doing to focus the lens was to simply line up the white line against a green or black number (feet / metres)

Then I realised that the white line does not rotate all the way around the feet and metre numbers because of two internal 180 degree metal stops. So I must be focusing wrong.

I can only find a manual for the Isoly mat camera online.

So can anyone please enlighten me as to the correct focus procedure, please

cheers Eric

Okay sorted!
Someone who has the same camera pointed out to me that the focus bezel containing the guide numbers had rotated out of position.

cheers Eric