Found a used but functional Koln column on eBay Germany. It didn't sell at the listed price. I contacted the seller and he sent more photos, including 2 videos that show the ignition functioning.
My plan is to take it apart, sand it, paint it and put it back together. I will likely install it in Nigel to run it until the restoration is underway, keeping the NOS Koln column as a spare.
Only missing the clip to hold the turn signal arm to the housing. I should have a spare in my cabinet.
It's worn in all of the right places.