Thats a mini not a C2, and it wouldnt be compatible with the lever.
C2 is closed(What the C bit stands for. All other brakes after them were open(hence the O bit in the first outing)
Righto, my hope knowledge is very limited, I’m a self confessed disc brake Luddite. The one I pictured was the remaining calliper from a pace rc36 kit. I just saw the no.3 and wildly jumped to an assumption. Now though, I know. The info is appreciated. Apologies to the OP for my stupidity