Next I took a marker and marked where I needed to cut the mudguard to make clearance for the chain guard.
I'm always a bit apprehensive cutting something expensive like this as it's easy to make a mistake, but I think it will be ok. I don't have a chain guard yet but I reckon I can make one easily enough when the time comes.
I held it in place while my wife eyed it up to ensure it was central. Here we noticed a bit of a problem. The lug on the frame is not sitting centrally so it tries to pull the mudguard to one side. You can counter act this by pulling the bottom of the guard to the other side and putting a twist in it, but I didn't want to do that. So off came the lug to be repositioned in the proper place.
Actually when I looked at the other frame it was worse. I really believe a lot of the frame building wasn't done in a jig at all. Somebody was just holding the bits together in roughly the right place while they were tacked.