Greybeard – i think your right
After a closer inspection it seems it might have been the stem that caused it. The stem isn’t a very snug fit around the steerer, about 1mm clearance all round, so it has ovalised the steerer when it was tightened.
I will have about 175mm of steerer left when I cut the cracked section off which probably isn’t long enough for most bikes so I won’t get much for the forks on eBay. So now im looking for a cheap second hand frame with a short headtube, a medium on one inbred seems a likely candidate
Great excuse to build a new bike i suppose, every cloud eh…