I succeeded in converting the second nüvi 250WT (also HWID 0827) into a nüvi 465T using Neil's instructions in post #28 and #40 (thank you, mate!). Screen shots below:
Strange thing though, is that after updating the FW with WebUpdater from v4.20 to v7.60, the unit is back to being a "normal" nüvi 250WT again without any truck supporting features. Yet, before updating, WebUpdater does recognize the unit as a nüvi 465! Anything I have overlooked or should have done besides what is mentioned in post #28 and #40?