LOWNDRAGON-Nice adaptation.I can't really tell how you attached the front most supports to the rear triangle-it looks a bit like hose clamps??
SSCOMP-You could adapt a seatpost rack-find a way to attach it to the rear triangle rather than the seatpost??
The easiest thing might be to use a seatpost type rack.Just make sure you have a sturdy seatpost-thick walled aluminum,not CF like the bike I quickly installed this rack one.You should be able to load-overload it to 20-25 lbs-no problem other than the effect on handling.Luck,Charlie
If you hung baskets from the rack,you would have less effect on stability-handling,but more total wt,so less carrying capacity.
What do you plan to carry that would exceed 15 lbs or so??