Two fine options for you:

Opiton 1: Get a lowrider front rack that attaches to Cantilever mounts instead of the mid-blade brazeon. Examples:
Tubus Smarti
VO Campeur front rack


Option 2: Get a front lowrider rack made for mid-blade brazeons and use a P-clamp or U-clamp to attach.
There are lots of bits for this available online.
Tubus makes a great kit especially for this.