The information at this Flickr page is what I needed: ... this is about the 1b, but the same applies to this camera, which I confirmed over at the ZICG is an 852/16 Ikoflex II.

I depressed the frame counter and turned it counter clockwise until it stopped. Then the film advance knob would turn only to a certain point and stop. The red indicator showed next to the viewfinder and the shutter-tension lever tensioned the shutter normally, after which the shutter release worked as well.

The fast speeds actually seem close. The slow speeds less so. 1/2 second is closer to 1 second and 1 second is closer to 2 seconds ... but 1/50 and up seem useable.

It's probably worth noting that all of this was possible even with the viewfinder hood closed.