I’m not getting any sensible search hits for “Ivar FM 750” but I found this document which seems to describe something very similar to what’s in your photos: https://amativeikals.lv/content/visiem_MR_0.pdf
If the valve is behaving the same as the MR 01 described in that document, it aligns with my schematic (with the “bypass” flow vertically upwards to the valve).