Here is Larry's picture of a Kirkham seam which is NOT on the top of the fender on what I believe is called an "unfiled" Kirkham body:
Now here is an "AC" produced CSX1000:
Here is a North Devon Metalcraft produced body (which could be a later CSX1000):
And Brooklands - AC Heritage:
It seems that the rest of these might have their sanded down weld seams at the top of their fenders.