Kask vertigo up and down retention system spares

About a year ago I treated myself to a Kask Vertigo and much to my delight very quickly proved all the great reviews and hype bang on..
Then whilst out riding one day felt a pull from the back on the helmet, at the time didn’t think much about it. When I got home I discovered that the dial/knob part of the adjuster in the retention system was missing.
Absolutely gutted, I immediately started trying to source the missing part in the Internet and quickly realised that the only spares you can find for any Kask helmet are the gel pads, for which there are literally hundreds of places you can them.
I’ve tried and tried to find the part but unfortunately have come up short.
I’ve tried all sorts of searches and different companies including Kask themselves for which I didn’t even get a reply for my enquiry.
I’ve also tried Velobrands and Velodrome shop but still no joy.
To make matters slightly worse I purchased the helmet from eBay so am exempt from the warranty and crash replacement scheme..
Presently I’m using my old MTB Bell helmet which doesn’t look great when I’m kitted out out in all my great cycling gear. I’m now on the verge of actually considering buying a second hand vertigo just to get this part..
Please please please does anyone know where I can find the missing part to make my prized helmet whole again?
I’ve (hopefully) attached some pics of the offending helmet.
Shaun