any brilliant ideas?

[scuderia]

It wouldn't be quick or easily reversable but why don't you cut the fender mounting out completely at the fork area and make the mounting bracket so the tubes of the fender braces weld to the new brake bracket?  That way you would have some rigidity at the adjuster that the fender bracket doesn't provide.

That's pretty much what I've decided.. going to mill out the backside to accommodate the adjuster and weld it in.. this will leave the outside of the brace looking original and if I do it right between the mount and the brace it should have plenty of support. Hope to make it look like it was cast/formed in....
thanks all for the help. new I'd figure out something.