Scan Area Adjustment - Off Center

I have a 3770 that has a problem with the scan area not being quite right. There appears to be padding on the left of the scan and a truncation on the right. I have found a document that appears to be published by Brother that outlines a Scan Area Fine Adjustment, but it does not seem to offer enough adjustment.

The same document goes into advanced repair and replacement procedures too but they aren't quite iFixit clear to understand.

Trying to find support through google or any other search engine is DOMINATED by brother for multiple pages so anyone else having this issue has no voice and we are prevented from helping each other.

My guess is that if I were to open the system up and bend the scan area or even add a shim to some part of the assembly, the whole thing would end up being absolutely perfect.

The document I'm referencing is the Brother Laser MFC SERVICE MANUAL and it covers:

DCP-9030CDN/L3510CDW/L3517CDW

DCP-L3550CDW/L3551CDW

HL-L3290CDW

MFC-9150CDN/9350CDW

MFC-L3710CW/L3730CDN/L3735CDN

MFC-L3745CDW/L3750CDW/L3770CDW

If anyone else is having scan area issues with this printer I'd be really keen to find out if they're the same issue I'm having or if this is the primary reason they ALWAYS seem to be available through Brother Refurbished.