I guess that that it is desirable that the "T" is firmly fixed to the axle to resist any chance if it moving under any stresses that may be imparted upon it by the flexy pipe movement as the axle rides the bumps, and which could then be transferred to the brake pipes risking fracture in time..?
I can't remember how it looks on mine, but does the clamp go to either side of the TEE? And now the new TEE is thicker so the ends of the clamp are farther apart?
If so, can you just put both sides of the clamp on the same side of the TEE? Maybe use a longer bolt?
Your IQ is a magnitude higher than mine - I wish I'd thought of that !!
Couldn't you just put a strip of rubber or aluminium under the clamp round the axle for it to nip up on?
A great suggestion - I was worried that the rubber may decay over time and lead to the stresses suggested by Luddite, but I think the combination of your suggestion and PaulyG's should do the trick
Thank you all for your collective wisdom !