Just to add to what Jeff & HP have already said...
Since your download sync speed was exactly the same, before & after removing the ring wire, but your SNRM improved to a staggering 23dB, I'd say HP is right - your line has been capped. The big SNRM is testament that your line is now a lot more stable, which confirms your line improvements have been effective and, in that respect, it is indeed a good thing. But SNRM is a trade-off against speed, and you would obviously prefer a a faster speed rather than a pointlessly massive SNRM.
BT's 'estimation' is, in most cases, actually just a reflection of your line's recent performance, so it becomes a self-fulfilling prophecy. IMHO they shouldn't call it an 'estimate'.
The evidence is that many ISPs help desks don't have the slightest understanding of line parameters, or DLM, or capping. As for the speed estimator, I harbour a suspicion that even BT don't understand how how it works, despite the fact they implemented it. But, unless you can persuade Orange to disregard the BT estimate, you may struggle to have the cap removed.
One thing that may help is to ask for an 'SNRM reset', or to have the line 'retrained'. But if Orange are as bad as other ISPs and that question is not on the script, you may find the helpdesk have simply no idea what you are talking about, and they will fob you off with some BS about the line's capabilities.
Judging from past threads concerning Orange, I'm afraid you could have quite a fight on your hands. I hope I'm wrong...