Here's an update: Just got home from work, IP Profile now UP at 4Mbps
In the BTW test I got 4.2Mbps Downstream and apparently the 'Max Achievable Speed' for my line is now 7.15Mbps. Router stats have not changed, noise margin is the same.
I assume the only thing left to happen now on my line is for the SNR Margin to fall back to 6Db (or wherever it was before the engineer came out), and then for the Sync speed to rise in accordance with that, and finally for the IP Profile to go up to its highest which would be somewhere around 7-8Mbps.
Does this sound right to you folks?