I'm not so confident, BB. It is nicely done of course, but you've got the reinforcement ending near the middle of the span of the rail. There will be a considerable stress concentration at that point, so with the long rail span on the 20" model, there still seems to be some potential for cracking. Time will tell, though it will probably take years to do so.
FWIW, I'd have preferred to see the reinforcement continue to the mid-point of the clutch mechanism platform.
