As said above. The 3 mounting holes are for a 2 bolt adapter that can be mounted to cater for either 24 or 26 inch wheels. You'll just need to confirm the hole spacing of some of the suggested adapters is the same as your frame, then happy days if so.
If not, and I'm no engineer (thankfully it seems based on opinions of them in another thread), you could probably quite easily make something. A rectangle of metal (Aluminium probably), a couple of holes to mount to your frame, a threaded hole for the brake mount (m8 or m10 are common sizes for these), then either a few holes drilled to retain the v brake spring tab, or similar to older pace forks, a little metal tab with a hole that the brake mount holds in place for the spring tab.
Probably wouldn't cost much, some off cuts of metal, assume you have a drill and some files. A cheap thread tap and your good. I could give you some brake mounts as I seem to have loads.