I got a custom front rack made in the middle of a tour, as I passed thru Newcastle upon Tyne, UK,.
generically a brake boss mount like #3, but adapted to my particular front brake ,
a Scott-Peterson SE.
.. 91, .. put my Film camera gear in a padded fanny pack on the front.

Custom means made for you, ask a framebuilder to make one just for you.

surely Van/Vic has some frame builders there , certainly are in Seattle.