Clamp blocks design

Ive been getting a bit stressed. Ive been getting a bit frustrated with people telling me how they would do it. I'm not proud of myself for this feeling - i spend most of my working days teaching people that they should be open minded to different ideas and approaches. However, I had these feelings of frustration and so I had to face up to them.
This rear-end attachment has created some debate. There are indeed, many ways I could skin this cat - and Ive become a bit attached to one specific idea. And its kinda hard to let go when suggestions are offered and I'm refusing to see how they can be any better. I have been of the mind to forget my tight budget and just go and get the clamp blocks engineered for me so i can focus on the frame (and not the component parts).
But I've taken some deep breaths and reflected on how my single-minded focus might be restricting my progress - and i think ive come up with a solution that should satisfy me on a number of levels;
1) the above solution is something that i can fabricate myself - thus saving me critical budget, AND fulfilling my "I-did-it-myself" requirement
2) it offers strength and integrity without compromising aesthetics or budget
3) I managed by the skin of my teeth to break away from my restrictive idea to find one that is better
As I say, I'm not proud of the fact that I got irritated by other ideas offered in good will - but i'm pleased that i recognised my poor behaviour and developed it. I shall try harder next time and I apologise here and now to anyone who i might have offended by not being interested enough in their suggestions (rest assured now that i have thought long and hard about all those comments and i think that you have all influenced the final outcome as seen in the sketch above)

So I shall make it out of box section (maybe 5mm is too thick - 3mm is probably quite good enough and the width is dependent on the diameter of the frame tubes) - i like this option because it will be relatively easy to make (i don't want to spend too much time making components for a project that is supposed to be a "conceptual" art piece - im a big-picture man, not a detail man). And I like the the way in this design that the clamping force between the two halves of the clamp blocks is through the faces of the box sections, and not onto the axle tube

I feel satisfied with the final design, guilty about getting irritated, and grateful for all the support and stimulation - please keep the ideas coming and remind me whenever I'm dismissive again