is there a supplier of these washers?
Or drill the frame to accept recessed brakes. But irreversible.As the others have said a spacer is required to avoid fouling.
Can't tell if the recessed nut fits into the fork, some have a smaller bolt hole.
If that's the case you need a nutted brake with a longer bolt
https://www.sjscycles.co.uk/brakes/diacompe-gc604-serrated-brake-washer/SJS Cycles also stock different lengths of brake fixing nuts if needed and all sorts of other brake spares.is there a supplier of these washers?