Skandix had the genuine 850 kit
1399234 and the S70 kit
1399411 listed but have been NLA for some time. They appear to still have the 5 door type
9499234.
It sure would be fantastic if you could manufacture a batch of these, Gareth, I have great admiration for your ingenuity and appreciate the time you have spent designing these but, as Luxobarge says, and with all due respect, the demand is going to be relatively low. If you could somehow significantly get the manufacturing costs down, perhaps then get the bigger suppliers onboard you may have a better chance of reaching a wider customer base. But even then will they sell?
Just to put the cost into perspective...€200 would have 4 sets bought and shipped from
VPARTS in Sweden. Unfortunately, for me, they still haven't sorted shipping to ROI