I have had multiple BG racks mounted to multiple bikes. The front racks are a pain if the bikes is not a BG or Robert Beckman (his early career partner) as they made mainly for BG and Robert Beckman forks. If your fork does not come with braze-ons in the appropriate place, I use "P" clamps (a silver P shaped bracket with a black plastic counting around the O part of the P). They are easily found in hardware stores like ACE Hardware for about $1 each. The threaded braze-ons are for fenders brackets. You may need to use spacers (sort of a like a hollow tube the screw passes thru) to mount the lower brackets. Do not ream the fork as you may want to eventually use another rack. P brackets are a lot cheaper than new forks.
Paired with Robert Beckman packs (BG copied them), they are a fantastically stable set. Not as waterproof as Ortleib packs but tremendously secure yet pretty easy to mount/dismount the packs.
Tailwinds, John