Offset valenced front mudguard.

Could it B that the bridge piece has been drilled/made on the slosh? The fork legs might be equal but what about the mudguard mounting studs? I would be very careful in 'slotting' as the guard/bracket can easily 'slop' back where it wants to B. Better to search for the real reason.

One of the shrouds on mine has a slightly lop sided inner top fixing disc.  It has a washer fitted above it to make it parallel.  It seems to be a problem with the pre-1964 narrow 7" fork spacing.

The mudguards were essentially unchanged as fas as I can make out.  Except for the pressed indent on each side to take the fork.  The bridges are different, to match.  Lots of earlier Dommies have scratches inside the shrouds.

If there's a real reason, I would first suspect the fixing flanges inside the shrouds to be slightly bent.  (I think I fitted the screws using a long cross head driver and Blutack to keep the screw in place)

My 65 Atlas’s left shroud was fouling the mudguard when I got it.  The chrome was worn through and the shroud wall thickness in the heavily scored contact area was wafer thin.  The shroud did not appear distorted or misaligned, nor she did the mudguard or bridge. The only thing I found wrong was that a wheel spindle for 7” forks was fitted, with only approx 2 full threads protruding past the slider for the nut.  Whether that would have contributed is unknown. As everything was dismantled for refinishing and has yet to be reassembled, I have yet to find out whether clearance will be better with all correct parts.

I agree with Al Os

Start with just the bridge and fix it securely in place with the four studs and nuts. Is it symmetrical? Equal distance, and enough distance, from both shroud lower edges as the forks are depressed. Suspect you will find it deformed, pushing the guard into one shroud.

Gets deformed when owners pinch the bridge inwards to clear the studs on fitting/removing.

Bridge checked. Add mudguard to bridge. Check clear again.

Add all four stays with loose bolts. Check clear again.

Then secure stays. Check again.

By now Robert, you will know if it was a deformed bridge, a stay too long or short, or the flat bit of the stays bent to the wrong angle.

Peter

We are on the right track at last. I have found so many variations with the stays that they are NOT to be trusted, different Models, mudguards etc. Get the bridge right with the mudguard where you want it then fit the stays to the mudguard. Do NOT let the stays 'push' you about.

This may be common knowledge... 

To remove the bridge undo all four nuts on the sliders. Remove the front wheel and axle. 

Push the bridge inwards at one side to clear the studs so that the fork slider can be rotated 180 deg (studs outwards). Then the same on the other side.

Now the bridge, or bridge and mudguard assembly can be moved downwards and out without scratches and scrapes. Or put back the same way and you squeeze the bridge the minimum.

Sorry if this is obvious, but it wasn't to me at first.

Peter