Thought so
just having a debate with a no return on ebay who sent me a 31mm yolk, he said it is of a 400/4 and wants me to explain why they dont fit.
I sent him info on people used the superdream forks on 400's as a replacement and obviously the one he is stripping had had this conversion to 31mm which are not correct spec for bike which i required.
Waiting for further response on return,but buyer protection should cover it as the are not as described.