We used the rack mounting stainless steel strips to bend a mount for the mudguard halves that is held by the brake Bolt .

LBS has Bin full of the strips. then you use the Bench-vise and a Hammer to make the bends ,
then poprivet the strips of mud guard on . perhaps you can Pay someone to do it for you?/

These may also be more than you are willing to spend Roadracer mk2 | Crud Products

I have most of my bikes fitted with proper Mudguards ..

maybe you can buy rain pants and a jacket to catch the wheel spray.

road grime will make washing off your bike frequently more important without good mudguards